Issue Attention and Legislative Proposals in the U.S. Senate
Jonathan Woon
Graduate School of Business
Stanford University
September 28, 2004
Abstract
What influences the attention legislators give to issues at the early stages of the legislative
process? At the early stages, policy alternatives are shaped through a number of effort-intensive
activities of legislators, but only a handful of these will be considered in subsequent collective
choice stages involving roll-call voting. Since there are many potential issues that may be
addressed, a fundamental aspect of lawmaking involves the choice of which issues to pursue and
how much to pursue them. This study examines how individual legislators allocate their
attention to issues by analyzing bill sponsorship in the U.S. Senate across a variety of issues and
several congresses. I find that although constituency interest, ideology, and party have moderate
impacts that vary from issue to issue, that influence over the agenda—in terms of membership
and leadership positions on relevant committees—is the single most important factor shaping
senators’ issue-specific attention.
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Introduction
Problems, concerns, and issues are never in short supply in politics. A few of these are
firmly planted at the central stage of public debate and political conflict. Others meander at the
periphery, periodically drifting into and out of public consciousness. Others consistently capture
the attention of an intense but small minority, and others still receive hardly any notice at all.
The political process establishes priorities among issues and produces variation in the amount of
attention issues receive. Schattschneider (1960) articulates this perspective in his classic work
on democratic politics:
There are billions of potential conflicts in any modern society, but only a few
become significant. The reduction of the number of conflicts is an essential part
of politics. Politics deals with the domination and subordination of conflicts. (p.
64, emphasis original)
Within the realm of representative politics, legislative institutions play a central part in
sorting out the relative importance of public concerns. Every two years, members of Congress
introduce several thousand bills and collectively whittle them down to a few hundred public
laws—along the way elevating some issues while lowering the status of others. At the final
stages of this process, legislators choose how to vote when faced with a handful bills and
amendments.
But how are those competing alternatives shaped? At the early stages of legislative
production, policy alternatives are shaped through the effort-intensive activities of legislators:
gathering information, drafting bills, building coalitions, and keeping pace with the activities of
various interests. In their book on trade politics, Bauer, Pool, and Dexter (1972) emphasize the
importance of the early stages of legislating compared to the final roll call stage:
The decisions most constantly on his mind are not how to vote, but what to do
with his time, how to allocate his resources, and where to put his energy. There
are far more issues before Congress than he can possibly cope with. (p. 405)
Thus, a fundamental aspect of both lawmaking and representation involves the choice of which
issues to pursue and how much to pursue them.
This study investigates a number of important questions regarding the way legislators
decide which issues are worth their time and effort in the shaping of alternatives. What
influences the attention legislators give to issues at the early stages of the legislative process? Is
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it interest driven, shaped by committee, or is it due to pressure from party organizations? What
is the role of constituency and the desire for re-election? Does any one factor dominate, or do
pressures vary from issue to issue?
To answer these questions, I undertake an empirical investigation of bill sponsorship as a
measure of issue attention. The outline of this paper is as follows. After reviewing related
literature on legislative effort, I provide a theoretical framework that identifies four general
factors expected to influence issue attention: preferences, national conditions, committee, and
party. I then discuss the data, which has important advantages over data used in previous
studies—including a panel structure that covers periods of both Democratic and Republican
control, and the classification of bills by issue. These features allow me to provide a more
refined picture of party, interests, and other factors that affect issue attention. Using negative
binomial regression analysis, I find that influence over the agenda—in terms of membership and
leadership positions on relevant committees—is the single most important factor shaping
senators’ issue-specific attention. I then conclude by discussing interpretations of this finding in
light of existing research on committees and participation.
Legislative Effort
As with any occupation, the job of a democratically elected representative requires time
spent working at the expense of engaging in other activities, such as leisure. Legislating is one
of a number of responsibilities that representatives are expected to perform (in addition to
oversight and constituency service), and as noted above, there are any number of issues on which
legislators can work. Consequently, one expects variation in both the amount of legislative effort
and in how that effort is directed. A number of scholars have been interested in understanding
such variation, and existing work encompasses several closely related concepts: specialization,
entrepreneurship, and participation. Although previous research shows that a number of factors
systematically influence how much policy-related work legislators undertake, our knowledge of
how that effort is directed towards issues is incomplete.
One dimension of legislative work is whether or not legislators specialize. As defined by
Matthews (1960), specialization involves focusing “energy and attention on the relatively few
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matters that come before his committees or that directly and immediately affect his state” (p. 95).
Using bill sponsorship and referral data, he constructed an “index of specialization,” which
supported his view that most senators tend to specialize, thus giving the pattern of behavior the
status as a norm. This research was the first to establish quantitatively the importance of
committee assignments on legislative work and set the tone for the subsequent literature.
In contrast, Sinclair (1989) portrays a contemporary Senate where specialization is no
longer the rule and where there are instead incentives for senators to be involved with as many
issues as possible. Constructing measures of specialization similar to Matthews’ (1960), she
finds that “just over half the senators who served in the 99th Congress fell into the generalist
category” (Sinclair 1989, p. 181).
In examining the choice of issues more directly with
interviews of Senate staff, she argues that senators have incentives to work both on issues that
come before their committees as well as issues that are outside their committees’ jurisdictions.
At most, the quantitative decrease in specialization and the plethora of incentives revealed by the
interviews suggest that it may not be possible to discover or generalize about patterns of issue
attention. At the very least, her findings suggest that in contrast to earlier eras, committee does
not play a very important role in structuring the work of modern senators.
Several studies use multivariate analysis and find a number of independent influences on
overall levels of legislative entrepreneurship. Frantzich (1979) studies a sample of House
members in the 94th Congress and interprets bill sponsorship as a measure of legislative effort.
Although his data analysis is rudimentary, he rules out electoral insecurity as a causal factor and
instead finds leadership effects (leaders introduce more bills than non-leaders) and partisan
effects (Democrats introduce more bills than Republicans). Schiller (1995) investigates bill
sponsorship in the Senate using both interviews and regression analysis. The interview data
provide support for the notion that the bills a senator introduces reflect “which issues he or she
wants to be associated with and the reputation he or she wants to acquire among colleagues,” (p.
187) while her quantitative analysis shows that the total number of bills a senator introduces is
systematically related to liberalism, the size of a state’s economy, committee assignments, and
committee leadership positions. Wawro (2000) constructs a more sophisticated measure of
legislative entrepreneurship using bill characteristics and finds that representatives’ efforts are
neither rewarded by constituents nor by campaign contributors, but instead rewarded with greater
influence within the House through promotions to committee and party leadership positions.
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Using an issue-by-issue empirical strategy similar to the one I use in this paper, Bratton
and Haynie (1997) find that a legislator’s race and gender affect bill sponsorship in state
legislatures. Their analysis covers a number of social issues (e.g. “women’s interests” and
“black interests”), and they find that partisanship and committee membership also have
significant effects.
Another form of legislative work is participation in the various stages of the lawmaking
process, and the most prominent work on this subject is Hall’s (1987, 1996). He analyzes billspecific participation and finds that it is positively related to a variety of factors, including
district and personal policy interests, committee and subcommittee membership and positions.
He also finds evidence of partisan effects that he attributes to the minority party’s lack of
influence over the agenda.
While the literature convincingly underscores the systematic influence of committee,
party, and other factors on early-stage specialization and legislative work, a number of questions
remain unanswered. First, what is the impact of committee relative to other factors in
determining specialization? A significant shortcoming in both Matthews’ and Sinclair’s analysis
of specialization is that neither accounts for the potential effects of constituency, so it is unclear
whether committees actually structure work or whether the observed behavior simply reflects
self-selection and constituency influence.
Second, what accounts for issue-specific investments of time and effort? The body of
work on legislative entrepreneurship generally fails to take into account the diversity of issues
and therefore overlooks this question. Although Schiller notes the importance of bill sponsorship
for establishing reputations on issues, her quantitative analysis does not consider issues at all and
therefore does not tell us much about agenda-setting. Wawro’s null findings about constituents’
response to entrepreneurship may be explained by this oversight. For example, if each district
cared about a different number of problems and constituents cared whether their representative
attempted to solve those problems, then there is little reason to expect any relationship between
overall legislative entrepreneurship and constituency response. Instead, we would expect
constituents to evaluate their congressman based on whether he worked on the problems that
interested them the most. Put another way, a hard-working legislator is not doing his job if all
that effort is spent on solving the wrong problems from his constituents’ perspective.
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Hall’s research goes beyond issue-specific attention in that he measures participation at
the level of individual bills. This is closer to what is needed, and while his data are appropriate
for a focus on participation, they cannot provide a complete picture of issue attention. The
problem is that participation is limited to the set of bills (and hence issues) that have already
been chosen at each stage of the legislative process—subcommittee, committee, and floor. In
other words, issue attention at each stage is conditional upon the individual and collective
choices about issue attention at the previous stage. Therefore, we can only begin to gain an
understanding of issue attention if we investigate the first stage of the legislative process.
This research begins to fill these gaps by analyzing early stage activity—bill
sponsorship—in an issue-specific way. This approach allows me to estimate the independent
effects of committee, party, constituency interest, and other factors so that we can properly learn
about what influences issue attention.
A Theoretical Framework for Issue Attention
In this section, I outline a theoretical framework that accounts for the attention that
individual legislators give to proposal-making activities. Like all people and organizations,
legislators possess finite amounts of time, effort, and resources with which to carry out their jobs
and pursue their goals. When confronted with a wide array of public concerns and issues, if a
legislator wishes to spend his effort and resources as efficiently as possible, then he faces an
allocation problem of the sort that has been well-studied in economics. A useful point of
departure for developing a theory of legislative attention is to think of the legislator’s decision
problem as one of constrained optimization. Standard results in microeconomic theory tell us
that allocation choices will reflect the structure of costs and benefits: consumers purchase goods
such that the ratio of marginal benefit and price is equal across goods and firms choose inputs so
that marginal profit equals marginal cost.
What are the costs and benefits of spending legislative attention? Consider the matter of
benefits first. I begin by postulating that legislators are policy-motivated, by which I mean that
their preferences are defined over policy outcomes. These preferences are assumed to be welldefined in the sense that every potential policy can be compared and that choices never exhibit
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cycles. A legislator benefits from the enactment of a new law or policy if he prefers that new
policy to the old one that it replaced.
Policy preferences are not considered primitive but rather are assumed to be derived from
a number of potential sources such as constituency (Mayhew 1974, Peltzman 1984), personal
convictions about “good public policy” (Fenno 1973), or party (McCarty, Poole, and Rosenthal
2001). The relative extent to which these sources induce preference and affect issue attention is
a major empirical question of the analysis.
Individual effort on the part of a single lawmaker is insufficient to produce benefits
directly because the production of policy by the legislature is a collective process. At the very
least, the votes of other legislators are required. Instead, paying attention to an issue yields
intermediate factors (or, equivalently, outputs) of legislative production: technical information
about the effects of policy, political information about the preferences and activities of other
members, and policy innovation in the form of specific ideas and legislative language. These
intermediate outputs are important because they provide legislators with greater potential
influence over the shaping of alternatives which will be voted on at later collective decision
stages of the lawmaking process. This claim relies on the assumption that creating policy and
drafting legislation is an imprecise process.
It is useful to express this argument using a simple model. Consider a single issue and
suppose that the policy space for that issue is one dimensional, where the status quo is represented
by the point Q. For simplicity, consider two legislators with symmetric and single-peaked utility
functions with ideal points at L and M—where M is the median legislator and L < M < Q < 2M-L.
The ideal points and the status quo are illustrated in the upper portion of Figure 1.
[Figure 1 about here.]
How might legislator L benefit from paying attention to this issue? Suppose that making
a proposal is costly so that L can only propose a policy if she pays some resource cost c. In
addition, suppose that making proposals is imprecise so that the legislator cannot specify an
exact alternative, but her proposal is instead the realization of a random variable. For
concreteness, assume that the distribution of the random variable is uniform between L and M
(depicted by the shaded rectangle). On the one hand, if she does not pay attention to the issue,
then with certainty L incurs no resource costs, and there will be no change in policy because she
has no alternative to propose. On the other hand, if L does pay attention to the issue she can
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propose some policy P, the exact location of which was drawn at random, and the median voter
then compares P to Q. With some positive probability, P will be closer to the median’s ideal
point, in which case it passes and becomes the new policy—thus producing policy benefits for L.
This happens when the realized value of P is between the vertical line at 2M-Q and M (for
example, P0). With the remaining probability, P is farther from M than Q (such as P1), in which
case it does not lead to a change in policy and therefore no new benefits. Legislator L will pay
attention to the issue if her expected utility minus the resource cost exceeds her utility from the
status quo policy. Thus, the model demonstrates how paying attention to an issue leads to the
generation of an intermediate output (the policy alternative) which in turn provides potential
influence because it leads to a chance—but not a guarantee—of a beneficial change in policy.
The model is also useful for showing how national policy conditions—represented by the
location of the status quo Q—affect the expected benefits of legislative attention. The farther
away the status quo is from the median’s most preferred policy, the greater are the expected
benefits of attention. (This is illustrated graphically by comparing part (a) with part (b) of Figure
1.) The intuition behind this result is as follows. When the status quo is farther away, three
things happen. First, there is an increase in the probability that the median will prefer the
realized value of P to the status quo. This corresponds to the leftward shift of the vertical line
from 2M-Q in part (a) to 2M-Q’ in part (b) and the resulting increase in the area between the
vertical line and the median’s ideal point. Second, the median will accept some policies that are
closer to L that he would reject when the status quo is closer: for example, point P1 in part (a) of
the figure. Third, for every realized value of P that the median accepts, the overall amount of
policy change is increasing as the status quo becomes more distant from L.
Now that the benefits of attention have been articulated, what about costs—how do the
costs of attention vary? I draw from previous research to identify factors that may affect the cost
of producing intermediate legislative outputs: committee membership and committee leadership.
Committee members face lower marginal costs of producing intermediate legislative resources
such as information and policy ideas. This may be because committee members are low-cost
specialists due to their backgrounds or previous experience with issues under their committee’s
jurisdiction (Shepsle 1978, Gilligan and Krehbiel 1987, Krehbiel 1991), or it may be that
committee members gain political information about each other as a byproduct of more frequent
interaction—what Hall refers to as a “transactional advantage” (1996, p. 91). Committee leaders
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face even lower marginal costs than the rank and file committee member because their control
over additional resources and the committee agenda effectively subsidize their production of
intermediate legislative products.
Aside from the premise that committee assignments and committee leadership lower the
marginal costs of legislative attention, it may also be that these factors raise the expected benefits
of attention because they indicate greater access to and influence over the legislative agenda—
the set of bills that will be considered in committees and on the floor. In other words, because
Congress can handle only a fraction of the bills that are introduced every session, legislators
must also take into account the probability that their work gathering information and promoting
alternatives will be relevant to the set of bills that are considered at all. Committee membership
raises this probability in two ways. First, a committee may recognize that its own members
possess greater issue-specific expertise relative to non-members and are therefore more likely to
consider legislation cosponsored by committee members (Wilson and Young 1997). Second, a
committee member possesses a vote that may affect whether a bill is sent to the floor once it is
considered by the committee. Although the probability that her vote is pivotal may be small, it is
nonetheless greater than that of the committee non-member. Committee leadership—especially
the chairmanship—raises this probability further since committee leaders possess procedural
prerogatives that allow them to establish the committee’s legislative priorities (Evans 1991,
chapter 2, Oleszek 2001, pp. 89-91).
Theories of strong parties in Congress also suggest that membership in the majority party
will contribute to a legislator’s decision to pay attention to issues. These theories generally argue
that the majority party will be able to influence its members to act cohesively on procedural
matters, and this claim naturally extends to influence over issue attention in a way that can be
incorporated into the present framework. One implication of conditional party government
(Aldrich 1995, Rohde 1991, Aldrich and Rohde 1997-98) is that the majority party has an
advantage in terms of resources:
If the conditional party government explanation is true, the majority will capitalize
on its majority status, and it will have and allocate more power and resources to its
party than the minority will be able to allocate for its uses (Aldrich and Rohde
1997-98, p. 548)
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These resources can be used by the majority party to subsidize the cost of attention to issues that
are important to the party (such as those most important to the party’s core constituency or
contributors).
The procedural cartel theory of Cox and McCubbins (1993, 2002) emphasizes the
majority party’s control over the legislative agenda and its consequences for the nature of
committee work:
If all of the most important agenda-setting positions are staffed by members of the
majority party, then the legislative agenda will certainly be affected. It will, at the
very least, be dominated by the interests of those members of the majority party
endowed with scheduling power. It may even reflect some sort of collective agenda
of the majority party… (Cox and McCubbins 1993, p. 260)
The implication is that majority party-favored issues and proposals are more likely than
minority-party favored issues to be considered in and reported from committee, as well as
scheduled for floor action. Thus, legislative attention should yield greater expected benefits for
members of the majority party.1
Data and Hypotheses
The theoretical discussion identifies four basic sets of factors that affect legislator’s issue
attention decisions: preferences, national conditions, committee, and party. To what extent does
each factor influence issue attention? Does one set of factors dominate? Are the effects the
same across issues, or are they conditional? These are questions that must be addressed by
systematic quantitative analysis.
To determine what kind of data are appropriate for an analysis of issue attention, two
preliminary questions must be considered. First, how can issue attention be quantified and
measured? Second, how should issues be defined and classified?
An ideal measure of issue attention would consist of the total amount of a legislator’s
personal and staff time devoted to researching, discussing, thinking about, or working on a
specific issue, perhaps weighted by the value of each person. Although quite difficult to observe,
1
Hall (1996, pp. 98-99) makes a similar argument with respect to participation.
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such data may be possible to obtain through surveys. Nonetheless, it would be very costly to
collect for an adequately sized sample and time period. Even if collected, establishing the
reliability of the measure, especially for any historical period, would be problematic at best.
Instead, bill sponsorship provides a readily observable, albeit imperfect, indicator of issue
attention. Bills are explicit policy alternatives that require time and effort to produce and are
therefore particular instances of the intermediate legislative outputs discussed in the previous
section. Other observable forms of attention include amendments and participation, both of
which occur at later stages in the legislative process and are constrained by the set of bills
already placed on the agenda. Since the theoretical framework for issue attention developed in
this study focuses on earlier, proposal-making related activities, bill sponsorship is the more
appropriate form of issue attention as it better reflects individual choices that are unconstrained
by the legislative agenda.
The data consists of public and private bills introduced by senators during the 101st
through 106th Congresses (1989-2000). The study covers periods of both Democratic and
Republican control of the Senate, and therefore an important benefit of the panel structure is that
it allows me to distinguish between party effects in ways that previous studies have not been able
to do. Only senators serving a nearly complete term were included in the data set, and there are
594 such senator-congress cases.2 The dependent variable in the quantitative analysis is the
number of bills introduced in a particular issue (e.g. agriculture), where an observation is a
senator-congress-issue triple.
Defining an appropriate set of issues is a daunting task inasmuch as the definition and
framing of issues is itself often the subject of political controversy (Schattschneider 1960). Riker
(1993a) prescribes the following criteria for social scientists: “the only escape from such futile
disputes about the specification of issues is to treat as issues whatever some people think are
issues” (1993, p. 3). I follow Riker’s advice and use the subject terms assigned to bills by the
staff of the Congressional Research Service (CRS) in the Library of Congress’ THOMAS online
database of legislation.3 The CRS assigns a set of subject terms to every bill for the purposes of
indexing and information retrieval. Although the CRS uses an indexing vocabulary that consists
of thousands of terms, they also assign each bill a single umbrella term (out of a set of 80 such
2
Excluded senators are those who left office during a congress between February of the first session and November
of the second session and their replacements.
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terms) that identifies the primary subject matter of the bill. I combine some of the original issue
categories to produce a set of issues more compatible with the independent variables introduced
later, resulting in a set of 66 issues. Thus, the total number of observations available in the data
set is 594 x 66 = 39,204.
The are two important benefits of using the CRS issue codes. The first is that they allow
for the disaggregation of bill counts by issue. Previous studies of legislative activity such as bill
sponsorship (Schiller 1995), cosponsorship (Koger 2003), and legislative success (Anderson et al
2003) examine overall levels of activity, but by design, such studies cannot account for issuespecific factors that motivate observed behavior. The second benefit is that the codings have
face validity and reliability. The case for validity stems from the fact that the coding system was
designed by professional librarians to be used by both policy-makers and researchers to find
legislation relevant to specific issues.
Overall levels of attention to issues are summarized in Table 1, which lists the twenty
issues with the most bills introduced during the period under study. Bills introduced for these
twenty issues account for a sizable portion (over 76 percent) of all bills. Many of these issues
are ones for which proposed legislation provides very targeted and particularistic benefits:
taxation, trade, and public lands figure prominently among the five highest ranking issues. The
table also lists the number of bills that become public law. Variation in bill passage rates is
apparent.
[Table 1 about here.]
The analysis focuses on nine specific issue areas. Three of these areas are of broad
public concern: crime, employment, and health. The other six issues, while they episodically
capture the attention of the broader public, are more typically of special concern to narrower
economic interests. They are agriculture, banking, communications, energy, trade, and
transportation. In all, 6,029 bills were introduced by senators in these areas.4
Table 2 presents summary statistics for the number of bills introduced in these nine issue
areas. The second column shows the proportion of member-congress cases for which at least one
bill was introduced and indicates that there are many zero-valued observations. Clearly, not all
3
4
Available at http://thomas.loc.gov.
Communications is not listed in Table 1 but is ranked 24th overall with 276 bills.
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members pay attention to each issue through bill introductions. This also suggests that the mean
number of bills in the third column is heavily influenced by the number of zero observations.
[Table 2 about here.]
The theory suggests that the analysis should focus on four major factors: preferences,
national conditions, majority party status, and committee. These are described in turn below,
along with the corresponding hypotheses. Summary statistics for continuous variables are
presented in Table 3.
[Table 3 about here.]
Preferences
Three types of preferences are common in the congressional literature: constituency
interest, ideological, and partisan. Although there is no consensus about whether members of
Congress are motivated by a single goal (e.g. Mayhew 1974) or a mix of goals (e.g. Fenno 1973),
to what extent each factor exerts an independent influence is ultimately an empirical question.
Thus, it is important to include measures of each type of preference in the analysis in order to
assess their relative weights. I now discuss the specific measures used and several corresponding
preference hypotheses to be tested.
Constituency induces preferences through the goal of re-election, so to the extent that a
senator is motivated by re-election, he will work on issues that are important to his constituency.
In particular, I hypothesize that bill sponsorship is increasing in constituency demand for each
issue.
Constituency demand is issue-specific, and I consider two ways in which an issue may be
important to the state constituency. The first is the degree to which people perceive the issue as
being a problem (Kingdon 1995, chapter 5), and this definition applies to issues of broad public
concern: higher crime is a problem, widespread unemployment is a problem, and difficulty
obtaining health care is a problem. As a problem worsens, constituents are more likely to be
concerned about that issue relative to other issues.
I use state-level policy indicators to measure issue salience. These data are available on
an annual basis and the average is computed for every two-year congress. For crime, the policy
indicator is the crime rate obtained from the FBI’s annual publication Crime in the United States,
which measures the incidence of serious violent and property crimes. For employment, I use the
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unemployment rate calculated by the Bureau of Labor Statistics. For health policy, the problem
indicator is the percentage of the population not covered by either a private or public health plan
(from the Current Population Survey). I hypothesize that each of these indicators will be
positively related to bill sponsorship. I also use the percentage of the population that is covered
by a government program (Medicare, Medicaid, military, or Veterans Administration health
care) as an additional indicator of health policy. I expect that this variable will be negatively
related to bill sponsorship since it indicates that there will be less constituency demand for new
health care programs.
The second way an issue may be important to the state constituency is if it is important to
the state’s economy. This definition of salience is used for the narrow economic issues. I use
data on gross state product (GSP) available from the Bureau of Economic Analysis to calculate
several measures of constituency economic interest. One set of measures consists of the
proportion of a state’s GSP for each of several relevant industries. These are shown as the
second group of variables in Table 3. The corresponding issues are listed in the second column.
For example, the percentage of GSP from farming measures constituency interest in agriculture,
the percentage of GSP from natural resources and utilities are relevant for energy, and so on.
Two general measures of economic interest are used to capture a state’s general demand
for policy-related legislation (as opposed to constituency service or pork). One is the overall size
of a state’s economy, measured in real dollars, which I expect to have a positive relationship with
bill sponsorship across all issues. The other is the degree of concentration in the state economy,
measured by calculating a Herfindahl Index from the industry-level measures.5 The index ranges
from 0 to 1 with higher values indicating greater concentration in fewer industries, and I expect
this variable to be negatively related to bill sponsorship.
Note that if the theory outlined above is incorrect insofar as members of Congress are not
policy-motivated but instead purely seekers of re-election—who allocate legislative attention
only so that they can engage in credit-claiming (Mayhew 1974)—then we would expect
constituency factors to be the only ones that matter.
The second type of preference is ideological. By ideology, I mean general beliefs about
what constitutes good public policy arising either from personal convictions or induced by
5
Let si∈(0,1) be the share of a state’s GSP from industry i. The index is H = Σ si2, where the sum is over the set of
industries.
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constituents’ beliefs. The operational definition I use is that ideology can be represented as a
liberal-conservative continuum where liberals prefer greater government regulation of economic
activity, while conservatives prefer less. One interpretation is that liberals may be more likely to
seek government solutions to problems through legislation, so I expect that more liberal senators
will tend to give more legislative attention to issues in terms of bill sponsorship.
An alternative interpretation is not that liberals prefer more legislation and conservatives
less, but that such positions represent the characteristics of the legislation that each type prefers.
If this is the case, then I expect that extremists will give more attention to issues at the bill
introduction stage than moderates. The reason is that extremists will generally have more to gain
from changes in policy (recall the discussion of policy distance in the theoretical section) and so
have greater incentives to do the leg work in the early stages, while moderates may wait until the
later stages to find moderate positions between competing extreme proposals.
To capture ideological preferences, I created two dummy variables based on the first
dimension of Poole and Rosenthal’s DW-NOMINATE ideal point estimates. One variable
captures liberal extremism and is coded 1 for the most liberal quartile of senators within each
congress, and the other variable captures conservative extremism and is coded 1 for the most
conservative quartile. The excluded category is the moderate two quartiles within every
congress.
The two dummy variable specification is necessary because it allows for two types of
flexibility in the analysis. The first is so that the analysis does not depend on the exact numerical
estimates of ideology that result from the assumptions of the NOMINATE method, which is
desirable because many roll call estimation methods differ in their point estimates but remain
highly correlated. The second type of flexibility is that it allows the data to decide if either of the
two interpretations of ideology affect issue attention. On the one hand, if liberals introduce more
bills than conservatives, then the liberal extremism variable will be positive while the
conservative extremism variable will be negative. On the other hand, if both types of extremists
introduce more bills than moderates, then both ideology variables will be positive.
The third source of preference is party. The theory of issue ownership in elections
(Petrocik 1996) and related research on campaign issue emphasis (Ansolabehere and Iyengar
1994, Sellers, 1998, Simon 2002) suggests that voters in the electorate associate different
political parties with the successful handling of different issues. One reason for that difference is
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that each party tends to pay more attention to issues of concern to its core constituency, so party
issue preferences are also constituency-induced. Of the issues considered in this study,
agriculture, employment, and health are often viewed as Democratic issues, while crime and
trade are often perceived as Republican. None of the other issues are party specific. To test
whether party constituencies affect issue attention, I include a dummy variable that is 1 for
Democrats and 0 for Republicans. If party constituency is an important influence on issue
attention, then the sign of this variable will be positive for agriculture, employment, and health,
and negative for crime and trade.
National Conditions
While state-level policy conditions tap the role of constituency influence, national
conditions indicate whether there are opportunities for policy change based on deficiencies in
existing law and policy. As the theoretical discussion suggests, if an issue—such as
unemployment—becomes a more serious problem, then legislative attention is more likely to pay
off in terms of shaping legislation and policy outcomes. The inclusion of national policy
conditions is especially significant because previous studies of legislative behavior have neither
considered nor estimated the effects of national policy conditions on individual legislative
activity despite the fact that scholars of agenda setting at the macro-congressional and macropolitical levels have recognized their importance (Walker 1977, Baumgartner and Jones 1993,
Kingdon 1995). This is therefore another important benefit of the data’s panel structure.
National condition variables are only included for the broad policy issues of crime, employment,
and health. The same indicators are used for national conditions as were used for state-level
importance, but are instead measured at the national level.
Majority Party Status
Contemporary theories of party government imply two additional hypotheses with respect
to party and issue attention. First, if the majority party’s control of institutional resources
subsidizes issue attention, then majority party senators are expected to introduce more bills than
members of the minority party for all issues. Second, if the majority party’s power lies in its
control of the legislative agenda, then a party’s senators will give more attention to issues that it
owns when that party is in the majority than when it is in the minority. Thus, the influence of
17
majority party status on issue attention will be both party and issue specific. In particular,
Democratic senators will introduce more bills on agriculture, employment, and health when in
the majority than the minority, while Republican senators will introduce more bills on crime and
trade.
To test these hypotheses, I include separate majority status dummy variables for each
party, which allows for flexibility in the specification similar to that for ideology: one variable is
coded 1 if a senator is a Democrat and in the majority, the other is coded 1 if a senator is a
Republican and in the majority, while both are coded 0 for all other possibilities. If the first
party status hypothesis is true, then the effect of both variables will be positive and significant
for all issues, while if the second party status hypothesis is true, then only the party that owns the
issue will see a positive effect on bill sponsorship.
Committee Factors
Previous research on legislative entrepreneurship, participation, and specialization
emphasizes the role of committee membership and leadership, and my theoretical discussion has
provided two mutually compatible rationales for why these factors are important influences on
issue attention. They either indicate lower marginal costs of producing intermediate legislative
resources (information and policy alternatives) or increase the probability that those resources
are relevant to issues considered later on the legislative agenda.
In order to assess the influence of committee factors on issue attention, I created a set of
three dummy variables indicating whether a senator is a member of a relevant committee, a
leader of one of its subcommittees, or a leader of the full committee.6 These categories are not
mutually exclusive so that a committee chairman will be coded 1 for both the membership and
full committee leadership variables. The committee assignment data used to create these
variables were collected from various editions of the Congressional Directory, while I
determined a committee to be relevant to an issue based on the pattern of bill referrals. Table 4
shows the proportion of bills for each issue that were referred to each of the committees listed
over the period spanning the 101st through 106th congresses. It is clear there is one committee
with primary jurisdiction over each issue except health, which comes under the jurisdiction of
6
I do not code subcommittee membership separately because almost all full committee members also sit on at least
one relevant subcommittee, making the two variables highly collinear.
18
both the Finance Committee and the Labor and Human Resources Committee.7 Accordingly, I
code the variables for the health issue based on whether a senator holds a position on either of
the two committees.
[Table 4 about here.]
I also interact these three variables with the two majority party status variables. The
interaction terms are useful for several reasons. First, they allow me to assess whether
committee and subcommittee chairmen devote more attention to issues than their ranking
minority counterparts, which we expect if they control both committee resources and agendas.
Second, I can determine whether the issue ownership hypothesis holds for committee leaders.
Third, the majority party hypotheses can be tested at the committee level.
Building on the theoretical discussion’s identification of preferences, national conditions,
committee, and party as general influences on issue attention, I enumerated a set of specific
factors and hypothesized about their effects. Preference variables include constituent interest (in
terms of both policy and economic indicators), ideology, and party affiliation. National
conditions are also measured with policy indicators. Issue-relevant committee membership was
identified by patterns of bill referrals. The panel structure of the data allows majority party
status to be measured independently of party affiliation. Furthermore, the data allow for
discrimination between alternative interpretations of ideology and party, which will provide a
clearer picture of their effects on issue attention.
Statistical Model
The dependent variable is the number of bills introduced by members in an issue area,
which takes on non-negative integer values, so specifying a count model is more appropriate
than linear regression. In count models, we are still interested in predicting the dependent
variable as a function of the data, but obtaining unbiased estimates requires that we take into
consideration the discrete and non-negative characteristics of the dependent variable. Recall
from Table 2 that there are many observations where legislators introduce no bills for a given
issue, which suggests that the data may exhibit greater dispersion than in the commonly used
7
Renamed the Committee on Health, Education, Labor and Pensions in the 105th and 106th congresses.
19
Poisson regression model. I therefore use the negative binomial regression model, which is a
generalization of the Poisson regression model that allows for overdispersion.8 In this model, the
dependent variable yi is assumed to be a draw from a distribution that is Poisson conditional on
the data Xi (containing all of the variables discussed in the previous section) and a stochastic
disturbance εi. The conditional mean of this distribution is
E[ yi | xi , ε i ] = exp( X i β + ε i )
where exp(εi) is assumed to have a Gamma distribution with mean 1 and variance α. The
stochastic component is analogous to the error term in the classical model and may be interpreted
as unobserved heterogeneity. The α term is referred to as the dispersion parameter, which is
estimated along with the coefficients β. If the estimate of α is significantly greater than 0, then it
confirms that the negative binomial model is more appropriate than a Poisson regression.
Results
The negative binomial regression model is estimated separately for each issue by
maximum likelihood, and the findings are presented in Table 5 for broad policy issues and in
Tables 6 and 7 for narrow economic issues. The first thing to note about the results is that we
can reject the hypothesis that the dispersion parameter is zero for every issue, which confirms
that using the negative binomial model is more appropriate than the Poisson.
[Tables 5, 6, and 7 about here.]
There are three columns for each set of estimates. The coefficients are presented in the
middle column and the standard errors in parentheses in the last column. Since the statistical
model is non-linear and the marginal effects are a function of both the coefficients and the data,
calculating first differences of the expected number of bills introduced is a useful way of
8
Alternative extensions, such as zero-inflated Poisson models, also take into consideration overdispersion due to a
greater preponderance of zeroes, but assume that the decision to introduce any bill is qualitatively different from the
number of bills introduced given that any bills are introduced. I assume that the process is not described by separate
decisions but instead by one decision where the censoring at 0 amounts to a corner solution in the senator’s
allocation problem.
20
quantifying the effects of the independent variables. A baseline expected number of bills is
calculated by setting all of the continuous variables at their average values and all of the
dichotomous variables to zero—which corresponds to an ideologically moderate Republican
senator in the minority who does not sit on any issue-relevant committees and is from an
“average” state. The calculated baseline values are presented for each issue in the row after the
last parameter estimate. For each independent variable, a comparison expected number of bills is
then computed by changing the value of the variable of interest while keeping all others at the
baseline values. Continuous variables are increased by one standard deviation while
dichotomous variables are changed from 0 to 1. The first difference is then obtained by
subtracting the baseline from the comparison, and these values are presented in the first column.
The presentation of the results is organized around three objectives of the quantitative
analysis: to determine which of the factors enumerated in the previous section influence issue
attention, to assess the relative importance of each factor, and to choose among competing
interpretations of factors.
The results in Tables 5 through 7 reveal that not all factors matter for every issue, and
Table 8 summarizes the significant coefficients by type of variable. Constituency and committee
factors affect nearly all issues. That is, for seven of the nine issues, there is at least one
constituency coefficient that is statistically significant at the 5 percent level. Committee
membership is significant for all issues but health, and at least one committee leadership
coefficient is significant for every issue but agriculture. Ideology has a bearing on a fewer
number of issues, as at least one ideology variable is significant for six issues. Party and national
conditions matter for the fewest issues: the effect of majority party status is significant for health,
agriculture, banking, and trade; Democrats introduce more bills than Republicans on trade only;
national conditions affect attention to health but not crime or employment.
[Table 8 about here.]
All of the significant committee coefficients are positive, as hypothesized, indicating that
committee members and leaders give more attention to issues under their committee’s
jurisdiction than do non-members. In terms of the size of the estimated effects, the analysis
shows that in general, committee variables have the largest influence on the expected number of
bills introduced. For the issues of broad concern, members of Judiciary introduce 1.59 more
crime bills than the baseline of 0.95 for non-members, and members of Labor and Human
21
Resources introduce 0.97 more bills than the baseline of 0.38. For the narrowly economic issues,
membership on Finance increases trade bill sponsorship the most (by 5 bills more than the
baseline of 1.34), while membership on Agriculture increases it the least (0.42 more than the
baseline of 0.37).
Occupying a position as committee leader increases the expected level of bill sponsorship
even further, and typically to a greater extent than committee membership alone. The effects of
leadership status also exhibit variation across issues in terms of both magnitude and which type
of leaders—i.e. subcommittee vs. full committee leaders, chairmen vs. ranking members—
sponsor more bills. Full committee leaders introduce 4.4 more crime bills, 2.72 more health
bills, 1.48 more energy bills, and 1.11 more transportation bills than rank and file members in
their respective committees. For these issues, the individual coefficients and additional joint
hypothesis tests also show that there is no statistical difference between committee chairmen
from either party and their ranking member counterparts. The only issue where the chairman’s
gavel strongly influences the number of bills sponsored is on trade, where the first difference is
an extremely high 32.58 bills.
In contrast to the impact of full committee leadership, subcommittee leadership
influences the behavior of chairmen but not ranking members. This is supported by noting that
the subcommittee leader coefficient is insignificant across all nine issues, but that holding a
subcommittee chairmanship has a significant effect for Democrats in employment, health,
banking, and communications, and for Republicans in communications. The first differences
show that the size of the effects are similar to those for full committee leaders. Democratic
subcommittee chairmen introduce 0.95 more employment bills than rank and file members, 2.62
more health bills, 1.28 more banking bills, and 2.56 more communications bills.
Communications policy is the only issue where the coefficient for the Republican subcommittee
chairman is significant, and the magnitude of the effect is very close to that of his Democratic
counterpart. In fact, while both coefficients are jointly significant, a Wald test cannot reject the
hypothesis that both coefficients are the same. Therefore, we can conclude that the
subcommittee leadership effect for communications policy is a chairmanship effect, while for
employment, health, and banking it is a Democratic chairmanship effect.
Two generalizations about leadership patterns within committees are noteworthy. First,
full committee leaders and subcommittee chairs tend not to pay attention to the same issues.
22
That is, there appears to be a division of labor within committee hierarchies, and this is observed
for every issue but health. Second, chairmen and ranking members cannot be distinguished at
the full committee level but behave differently at the subcommittee level. This suggests that the
effect of agenda influence varies according to the level of hierarchy.
The impact of constituency interest on bill sponsorship varies widely from issue to issue.
For most issues, economic interest appears to exert modest influence, while the severity of policy
problems has no impact whatsoever. Crime and trade issues exhibit the greatest impact of
economic size, with increases of 0.56 and 0.74 more bills, respectively, but the effects are far
smaller than the committee and leadership effects for those issues. The effect of general
economic interest is pretty much negligible for the remaining issues. A one standard deviation
increase in economic size leads to 0.10 more employment bills, 0.09 more agriculture bills, 0.14
more transportation bills, and 0.03 less communications bills. Increased economic concentration
leads to 0.11 fewer employment bills and 0.10 fewer transportation bills—although the
coefficients are in the hypothesized direction, they are substantively unimportant.
Direct economic interest significantly affects senators’ bill sponsorship behavior for
agriculture, health, and trade bills. Increasing the importance of farming to a state by one
standard deviation increases the expected number of bills sponsored by 0.26 bills. Although the
summary statistics in Table 3 show that the mean percentage of GSP due to farming is 1.99
percent and the standard deviation is 2.25, the maximum is 11.70 percent, which indicates a
skewed distribution. If the importance of farming is increased from the mean to the maximum
instead of by one standard deviation, a senator would introduce 3.44 more bills. This shows that
farm state senators are very responsive to constituency interest. The introduction of trade bills is
positively related to manufacturing (0.34 more bills) and negatively related to farming (0.28 less
bills). Agriculture and trade are issues that are commonly characterized as highly distributive,
where legislation frequently provides concentrated benefits to constituents, so it is not
unexpected that there are constituency effects. It is somewhat surprising, however, to find that
attention to health policy depends on the size of the health services industry instead of the status
of health care as a policy problem.
Similar to the constituency variables, ideology has a modest impact on attention to most
issues, although the interpretation of these effects is not entirely clear. The ideological
extremism effects are jointly significant for employment, health, banking, energy, trade, and
23
transportation. The largest effects are for health, where liberal extremists tend to introduce 0.82
more bills than moderates and conservatives introduce 0.87 less bills. The next largest effect is
on trade, where conservative extremists introduce 0.74 more bills. Since the coefficients run in
the opposite directions for all six of these issues, we can safely reject the hypothesis that
extremists sponsor more bills than moderates. Neither can we entirely embrace the interpretation
that liberals will introduce more bills than conservatives either, because the effect of ideology on
trade bill sponsorship runs counter to this hypothesis. A third interpretation of ideology is more
consistent with these findings: that in addition to holding similar positions across issues,
ideologically similar senators also share alike issue priorities.
The analysis shows that when compared to constituency and ideology, party affects fewer
issues but that the relative impact is approximately the same. For instance, Democrats introduce
0.84 more trade bills and 0.86 fewer health bills than when in the minority, while Republicans
introduce 0.5 fewer trade bills.
The data, however, also indicate that role of partisanship is more complex than originally
anticipated. Nevertheless, several party effects can be ruled out. First, there is very little support
for the hypothesis that partisan differences influence attention independent of constituency
economic interest and ideology. The only significant effect is for banking bills, which is both
unexpected (since it is not an issue owned by either party) and small in magnitude (Democrats
introduce 0.23 less bills than Republicans). Second, there is little support for the hypothesis that
partisanship works through committee. When Democrats are in the majority, they sponsor 0.6
more agriculture bills, but none of the other committee membership and party interactions are
significant.
Third, the hypothesis that the majority party’s control of resources and the agenda allow
it to subsidize the attention costs of its members can be soundly rejected. Three of the five
individually significant majority party coefficients are negative, which is opposite of the
hypothesized direction. Further evidence against the hypothesis is that while for health, banking,
and trade issues, the majority party coefficients are jointly significant, their influences move in
opposite directions. When Democrats are in the majority, they introduce more banking and trade
bills and fewer health and agriculture bills, while Republicans in the majority sponsor more
health bills and fewer banking and trade bills. That the effect of majority party status works not
through committee but on the party membership as a whole suggests these patterns may be
24
consistent with the issue priorities of party leadership rather than due to the consolidation of
subcommittees that the Republicans instituted upon assuming majority control of the Senate.
Exploring such a possibility is of secondary importance, however, given that committee factors
outweigh party effects and would require an analysis of leadership agendas that goes beyond
what the data in this study allow.
Summary
The analysis of bill sponsorship across a variety of issues from the 101st through 106th
Senates leads to a number of noteworthy findings about the nature of issue attention and
legislative work. The central finding is that committee membership is the dominant influence on
senators’ attention to issues: committee members give more attention to issues under their
jurisdiction than non-members, and committee leaders pay even more attention than rank and file
members. This result is not only consistent with the consensus in the existing literature that, to
quote Fenno (1973), “committees matter” (also Matthews 1960, Frantzich 1979, Schiller 1995,
Hall 1996) but also enhances that view by showing that committee positions matter most, despite
Sinclair’s contention that “almost all senators are also involved in issues outside the jurisdiction
of their committees” (1989, p. 148).
The effects of constituency, ideology, and party are significant to a lesser extent, and the
analysis in this paper also begins to provide a more refined and complete account of the
relationship between these factors and issue attention. First, not all factors matter, or matter for
every issue. Notably, basic party affiliation does not distinguish senators’ interest in an issue.
Second, a mix of issues typically influences attention. For example, both constituency economic
interest and ideology appear to induce preferences for changes in health policy. As Table 8 also
shows, this mix also varies from issue to issue—only two pairs of issues share the same types of
effects (communications and crime, and employment and transportation). These findings
suggest that the relative importance of various sources of preference is not primitive. That is, the
results indicate that it is not possible to classify senators according to whether they are primarily
re-election or policy motivated, as Fenno (1973) does, but that such classifications must be
conditioned upon the issue under consideration. Even issues within committees appear to evoke
different sources of interest. Table 8 shows this for three committees that handle more than one
25
issue examined in this study (Finance, Labor and Human Resources, Commerce, Science, and
Transportation).
Although the results demonstrate that both majority party status and ideology affect issue
attention, neither do in ways that were initially expected. The effect of ideology on issue
attention is certainly not an extremism effect, which differs from what Kessler and Krehbiel
(1996) find for cosponsorship, nor is it a liberalism effect, as Schiller (1995) argues for bill
sponsorship. Instead, ideology seems to reflect similarity in issue priorities in addition to the
more common view that it reflects similarity in issue positions (i.e. Poole and Rosenthal 1997).
For any given issue where majority party status matters, it works in opposite directions for each
party, and often in opposite directions than would be predicted based on the notion of issue
ownership. These results are puzzling, yet may be explained by party leadership agendas—a
possibility that future research should investigate.
Finally, national policy conditions matter very little, and state policy conditions do not
matter at all. This finding seems to be at odds with longitudinal studies of attention to single
issues (Walker 1977, Baumgartner and Jones 1991, Kingdon 1995) which find that the severity
of problem indicators plays an important role in raising politicians’ awareness of an issue. In
previous studies, however, issues are defined at a greater level of specificity (e.g. Baumgartner
and Jones’ study includes issues such as nuclear power, pesticides, and smoking), and it may be
that the issues here encompass a steady stream of smaller problems. That is, if there is a constant
flow of problems on the congressional agenda that exceeds the Senate’s lawmaking production
capacity, then legislative issue attention would not vary with the salience of items on the
congressional agenda, which is what the data suggest.
Interpretations
Why does committee membership and leadership structure issue attention? The
arguments put forth in this paper are that committee positions reflect lower costs of legislative
production (e.g. due to expertise and low-cost specializiation) as well as greater access to and
influence over the agenda. These theoretical claims are consistent with Hall’s (1996)
explanation of participation. In contrast to his findings (see also Hall 1987), however, my
26
analysis demonstrates that various forms of interest play only modest roles in motivating
attention to legislative proposal-making.
One might argue that because of self-selection, observed committee effects instead
capture differences in interest between members and non-members. The industry-specific
constituency variables were chosen to capture narrow economic interests, however, so it is
doubtful that there is an omitted variables problem. Nevertheless, some additional investigation
is useful to rule out this possibility. If there is bias in the estimated coefficients due to an omitted
variables problem, then we would expect that they overstate the importance of committees. We
can assess the potential severity of this bias by re-estimating the statistical model for agriculture
and trade. These issues represent the best case scenarios for an a priori belief that the industry
variables for farming and manufacturing correspond closely to the true levels of constituency
interest, and indeed this is confirmed by their significance in Tables 6 and 7. Thus, if we assume
there is no bias for either of these two issues, then estimating equations from which constituency
interest has been omitted will give an idea of the extent of potential bias in the committee
coefficients for the remaining issues. This exercise reveals that the potential bias is small. For
agriculture bills, the coefficient for committee membership increases from 0.76 to 0.91, and the
corresponding change in the first difference is an increase from 0.42 to 0.60. For trade bills, the
coefficient increases from 1.55 to 1.59 and the first difference increases from 5.00 to 5.74. In
both cases, the difference is minor.
Changes in bill sponsorship before and after a senator changes committees provide
further evidence against the self-selection interpretation. If a senator transfers to a committee in
which he has a high demand for policy on a specific issue, say trade, then presumably he has
been sponsoring many trade bills prior to his committee transfer as well. Table 9 shows that
instead, bill sponsorship increases for an issue after transferring to a relevant committee. The
increase is statistically significant for broad issue bills, while for narrow economic bills there is a
small increase, but it is not statistically significant. Interestingly, when a senator transfers off of
a committee, the decrease in narrow interest bills sponsorship is small, while the average number
of broad interest bills increases—consistent with notion that a senator acquires expertise during
the course of committee membership.
[Table 9 about here.]
27
Thus, irrespective of whether committees are composed of homogeneous high-demand
preference outliers, interest is not the driving force behind issue attention. The results of this
paper therefore leave us with a refinement of the above question: why does committee structure
attention in the absence of observable interest?
This investigation has focused on which issues senators spend their legislative resources,
whereas prior research has puzzled over why legislators do the “highly detailed, dull, and
politically unrewarding” (Matthews 1960, p. 94) work of the Congress in the first place. Hall’s
(1996) perspective is typical:
The timeliness, expertise, and efficiency with which Congress makes policy
decisions—that is, the reputed consequences of the member’s duteous work—are
all public goods. Why would a member participate in their production? Why not
free ride? Why not let Representative Schmuck do it? (p. 50)
From this point of view, understanding how committees provide selective incentives for
members to undertake costly effort (when coupled with the jurisdictional boundaries of the
committee system) would help explain why issue attention is structured by committee positions.
Existing theories, however, provide little guidance, as they tend to embody assumptions
about features specific to the House. Regardless of whether one believes that restrictive rules
enforce gains from trade (Weingast and Marshall 1988) or induce committees to acquire
information (Gilligan and Krehbiel 1987, Krehbiel 1991), such rules protect the work of
committees, thus providing them with a degree of power. This power selectively benefits
members of the committee and in turn motivates representatives to participate in dull legislative
work. The Senate, of course, does not use closed rules, and even invoking cloture does not
preclude amendments.
A recent study by Wawro (2000) concludes that House members are motivated to engage
in legislative entrepreneurship by the prospect of being reward with promotions to prestigious
and powerful committee and party positions. The basis for this motivation is representatives’
desire for what Fenno characterizes as “influence within the House” (1973, p.1). Fenno
observes, however, that “if we could adduce a generalization, it is that Senators are less
concerned about using their committees to enhance their inside influence than are House
members” (1973, p. 145). For a number of reasons, similar incentives are not likely to be present
in the Senate, chief of which is that it is the rare majority party senator who does not chair at
28
least one subcommittee. During the 101st through 106th Senates, the minimum percentage of
majority party senators holding a chairmanship of a standing committee or one of its
subcommittees was 80.7 (Ornstein, Mann, and Malbin 2000, p. 123) and a senator chaired at
least 1.6 committees or subcommittees on average.9 Hence, simply being a member of the
majority in the Senate is enough to provide what the House member must earn through hard
work.
If committee work in the Senate is not protected by restrictive rules or rewarded with
influence within the chamber, then it seems truly puzzling that senators would voluntarily do the
work to provide legislative public goods. It is only bewildering, however, because the nature of
public goods has been fundamentally misunderstood when applied to political action. Although
the non-rival consumption property of public goods certainly leads to incentives to free ride, this
only implies that public goods will be inefficiently provided. It by no means implies a failure to
provide any public good at all. Whether or not it does depends on individual costs and
benefits—values to be determined empirically, not assumed a priori. Indeed, Olson (1965)
remarks in his seminal work on collective action that:
Though there is a tendency for even the smallest groups to provide suboptimal
amounts of a collective good…the more important point to remember is that
some sufficiently small groups can provide themselves with some amount of a
collective good through the voluntary and rational action of one or more of their
members. (p. 33)
The analysis in this paper has shown that collective goods are in fact provided by both
members and leaders of Senate committees, and I have argued that this is due to a combination
of lower costs and influence over the agenda. Olson’s work suggests that group size is an
additional factor that may be fruitfully incorporated into a more refined theory of legislative
participation and issue attention. In short, low-cost specialization, influence over the agenda,
and small groups conspire to provide senators with opportunities to legislate, which they take
advantage of even if not originally motivated by identifiable personal or constituency interest.
The experiences of two senators are instructive. In Fenno’s (1989) study of Dan
Quayle’s first term in the Senate, he observes a remarkable transition from a lazy and inattentive
9
In the House, at least 43.8 percent of majority party representatives held a chairmanship and as few as 4 held
multiple chairmanships.
29
representative to an accomplished Senate subcommittee chairman largely responsible for
producing the Job Partnership Training Act, an issue the senator did not seek out:
The conjunction of the senator and the subject matter was purely accidental.
Nothing in Quayle’s previous experience would have led anyone to expect him to
be especially interested in—much less influential in—this area of policy…Once
he had positioned himself on a committee and on a subcommittee, the subject of
job training fell into his legislative lap. (p.2)
Similarly, Asbell’s (1978) chronicle of Ed Muskie’s experiences also describes how committee
assignments largely determined which issues the senator worked on. For instance, a staffer notes
that “the work of the Senate has thrust on him certain issues, which he may not have chosen” (p.
120). Furthermore, despite receiving quite undesirable committee assignments in his first term—
being “banished to his fourth choice, Banking and Currency, and to the Siberias of Public Works
and Government Operations” (p. 121)—his assignment to Public Works provided a suitable
position for advancing what would become his signature issue: the environment.
Conclusion
The aim of this study was to learn about issue selection in the governmental arena by
determining how individual legislators allocate lawmaking effort to different political issues. By
analyzing bill sponsorship in the Senate, I find that constituency interest, ideology, and party
have moderate impacts that vary from issue to issue, but more importantly, that committee
membership and leadership are the dominant influences. A bold conclusion that might be drawn
from the results is that senators stumble upon issues more often than they actively seek them out.
A more modest conclusion, however, is that senators pursue issues within the set of opportunities
provided by their committee assignments. In light of existing research on legislative committees,
entrepreneurship, and participation, this suggests that by dividing labor, the committee system
serves to coordinate the work of the Senate, even though it may not necessarily provide
additional motivation to do so. Why is the committee system so important in structuring the way
senators attend to issues? I have suggested that committees provide opportunities to legislate,
and it remains for future research to develop this into a more precise theoretical explanation.
30
References
Aldrich, John H. 1995. Why Parties? The Origin and Transformation of Party Politics in
America. Chicago: University of Chicago Press.
Aldrich, John H. and David W. Rohde. 1997-1998. The Transition to Republican Rule in the
House: Implications for Theories of Congressional Politics. Political Science Quarterly
112: 541-567.
Anderson, William D., Janet M. Box-Steffensmeier, and Valeria Sinclair-Chapman. 2003. The
Keys to Legislative Success in the U.S. House of Representatives. Legislative Studies
Quarterly 28: 357-386.
Ansolabehere, Stephen D. and Shanto Iyengar. 1994. Riding the Wave and Claiming
Ownership Over Issues: The Joint Effects of Advertising and News Coverage in
Campaigns. Public Opinion Quarterly 58: 335-357.
Asbell, Bernard. 1978. The Senate Nobody Knows. New York: Doubleday & Company
Bauer, Raymond A., Ithiel de Sola Pool, and Lewis Anthony Dexter. 1972. American Business
& Public Policy: The Politics of Foreign Trade, 2nd ed. Chicago: Aldine Publishing
Company
Baumgartner, Frank R. and Bryan D. Jones. 1993. Agendas and Instability in American
Politics. Chicago: University of Chicago Press.
Bratton, Kathleen L. and Kerry L. Haynie. 1999. Agenda Setting and Legislative Success in
State Legislatures: The Effects of Gender and Race. Journal of Politics 61: 658-679.
Campbell, James E. 1982. Cosponsoring Legislation in the U.S. Congress. Legislative Studies
Quarterly 7: 415-422.
Cox, Gary W. and Mathew D. McCubbins. 1993. Legislative Leviathan: Party Government in
the House. Berkeley: University of California Press.
Cox, Gary W. and Mathew D. McCubbins. 2002. Agenda Power in the U.S. House of
Representatives, 1877-1986, in David W. Brady and Mathew D. McCubbins, eds., Party,
Process, and Political Change in Congress: New Perspectives on the History of
Congress. Stanford, Calif.: Stanford University Press.
Evans, C. Lawrence. 1991. Leadership in Committee: A Comparative Analysis of Leadership
Behavior in the U.S. Senate. Ann Arbor: University of Michigan Press.
Fenno, Richard F., Jr. 1973. Congressmen in Committees. Boston: Little, Brown and Company.
31
Fenno, Richard F., Jr. 1989. The Making of a Senator: Dan Quayle. Washington, D.C.: C.Q.
Press.
Frantzich, Stephen. 1979. Who Makes Our Laws? Legislative Studies Quarterly 4: 409-428.
Gilligan, Thomas and Keith Krehbiel. 1987. Collective Decision-Making and Standing
Committees: An Informational Rationale for Restrictive Amendment Procedures.
Journal of Law, Economics, and Organization 3: 287-335.
Gilligan, Thomas and Keith Krehbiel. 1989. Organization of Informative Committees by a
Rational Legislature. American Journal of Political Science 34: 531-564.
Hall, Richard L. 1987. Participation and Purpose in Committee Decision-Making. American
Political Science Review 81: 105-128.
Hall, Richard L. 1996. Participation in Congress. New Haven: Yale University Press.
Kingdon, John W. 1995. Agendas, Alternatives, and Public Policies, 2nd ed. New York:
Longman.
Kessler, Daniel and Keith Krehbiel. 1996. Dynamics of Cosponsorship. American Political
Science Review 90: 555-566.
Koger, Gregory. 2003. Position Taking and Cosponsorship in the U.S. House. Legislative
Studies Quarterly 28: 225-46 .
Krehbiel, Keith. 1991. Information and Legislative Organization. Ann Arbor: University of
Michigan Press.
Matthews, Donald R. 1960. U.S. Senators and Their World. Chapel Hill: University of North
Carolina Press.
Mayhew, David R. 1974. Congress: The Electoral Connection. New Haven: Yale University
Press.
McCarty, Nolan, Keith Poole, and Howard Rosenthal. 2001. The Hunt for Party Discipline in
Congress. American Political Science Review 95: 673-688.
Oleszek, Walter J. 2001. Congressional Procedures and the Policy Process, 5th ed.
Washington, D.C.: CQ Press.
Olson, Mancur. 1965. The Logic of Collective Action: Public Goods and the Theory of Groups.
Cambridge: Harvard University Press.
Ornstein, Norman J., Thomas E. Mann, and Michael J. Malbin. 2000. Vital Statistics on
Congress, 1999-2000. Washington, D.C.: AEI Press.
32
Peltzman, Samuel. 1984. Constituent Interest and Congresional Voting. Journal of Law and
Economics 27: 181-210.
Petrocik, John. 1996. Issue Ownership in Presidential Elections, with a 1980 Case Study.
American Journal of Political Science 40: 825-850.
Poole, Keith and Howard Rosenthal. 1997. Congress: A Political-Economic History of RollCall Voting. Oxford: Oxford University Press.
Riker, William H. 1993. Introduction to Agenda Formation. Ann Arbor: University of
Michigan Press.
Rohde, David W. 1991. Parties and Leaders in the Post-Reform House. Chicago: University of
Chicago Press.
Schattschneider, E.E. 1960. The Semisovereign People: A Realist’s View of Democracy. Fort
Worth: Harcourt Brace Jovanovich.
Schiller, Wendy J. 1995. Senators as Political Entrepreneurs: Using Bill Sponsorship to Shape
Legislative Agendas. American Journal of Political Science 39: 186-203.
Sellers, Patrick J. 1998. Strategy and Background in Congressional Campaigns. American
Political Science Review 92: 159-171.
Shepsle, Kenneth A. 1978. The Giant Jigsaw Puzzle: Democratic Committee Assignments in
the Modern House. Chicago: University of Chicago Press.
Sinclair, Barbara. 1989. The Transformation of the U.S. Senate. Baltimore: The Johns Hopkins
University Press.
Simon, Adam F. 2002. The Winning Message: Candidate Behavior, Campaign Discourse, and
Democracy. Cambridge: Cambridge University Press.
Walker, Jack L. 1977. Setting the Agenda in the U.S. Senate: A Theory of Problem Selection.
British Journal of Political Science 7: 423-445.
Wawro, Gregory. 2000. Legislative Entrepreneurship in the U.S. House of Representatives.
Ann Arbor: University of Michigan Press.
Weingast, Barry R. and William J. Marshall. 1988. The Industrial Organization of Congress; or,
Why Legislatures, Like Firms, Are Not Organized as Markets. Journal of Political
Economy 96: 132-163.
Wilson, Rick K. and Cheryl D. Young. 1997. Cosponsorship in the U.S. Congress. Legislative
Studies Quarterly 22: 25-43.
33
Figure 1. Preferences and policy search
2M-Q
(a)
L
P1
P0 M
Q
2M-Q’
(b)
L
M
Q’
Table 1. Major issues and bill introduction activity
Rank
Issue
Bills
Percent
of Total
1,661
9.56
Trade
1,451
Health policy
1,048
Public lands
5
Public
Success
Laws
Rate
Enacted
0
0.0%
8.35
4
0.3%
6.03
30
2.9%
900
5.18
118
13.1%
Crime
815
4.69
30
3.7%
6
Environment
635
3.66
12
1.9%
7
Transportation
618
3.56
27
4.4%
8
Private legislation
596
3.43
32
5.4%
9
Social security
553
3.18
1
0.2%
11
Education
534
3.07
18
3.4%
10
Defense
534
3.07
14
2.6%
12
Energy and Natural Resources
511
2.94
30
5.9%
13
Foreign policy
499
2.87
20
4.0%
14
Employment and Labor
474
2.73
12
2.5%
15
Agriculture
466
2.68
23
4.9%
16
Law
437
2.52
28
6.4%
17
Veterans
421
2.42
19
4.5%
18
Commemorative legislation
401
2.31
77
19.2%
19
Budgets
394
2.27
3
0.8%
20
Banking and Finance
370
2.13
18
4.9%
1
Taxation
2
3
4
34
Table 2. Summary statistics for bill introductions
Issue
Percent of
non-zero
observations
Mean
Std. Dev.
Max
34%
29%
26%
49%
36%
41%
57%
55%
46%
41%
0.78
0.62
0.46
1.36
0.79
0.84
1.75
2.42
1.04
1.12
1.59
1.53
1.23
2.36
1.59
1.68
2.93
4.84
1.70
2.48
12
16
12
17
17
18
23
48
13
48
Agriculture
Banking
Communications
Crime
Employment
Energy
Health
Trade
Transportation
Total
Bills Introduced
Table 3. Summary statistics for continuous independent variables
Variable
Issue(s)
State Crime Rate
Crime
State Unemployment
Employment
State Uninsured
Mean
Std. Dev.
Min
Max
47.98
12.51
23.41
88.08
5.27
1.49
2.50
11.00
Health
13.90
3.91
6.40
24.80
Govt Health Care
Health
27.68
4.27
18.25
40.35
Health Services
Health
6.45
1.32
2.07
9.98
Farming
Agriculture, Trade
1.99
2.25
0.08
11.70
Financial Services
Banking
5.21
3.98
1.52
31.32
Communications
Communications
2.78
0.96
1.36
8.41
Natural Resources
Energy
2.82
5.99
0.01
36.02
Utilities
Energy
3.33
1.25
0.85
8.91
Manufacturing
Trade
19.04
7.32
3.26
34.24
Transportation
Transportation
3.70
1.09
1.57
7.63
U.S. Crime Rate
Crime
51.91
5.67
41.96
57.88
U.S. Unemployment
Employment
5.57
1.03
4.10
7.15
U.S. Uninsured
Health
15.00
0.77
13.75
16.20
U.S. Govt Health Care Health
27.49
1.04
26.05
28.95
Econ. Size
All
11.38
1.04
9.47
14.01
Econ. Concentration
All
0.15
0.02
0.12
0.20
35
Health
Trade
1.0
0.2
2.2
1.3
0.2
2.4
0.8
0.8
73.1
0.2
0.5
0.6
0.2
8.1
0.1
23.7
0.7
2.1
18.6
2.8
43.3
92.6
2.9
18.9
1.8
0.6
1.2
0.4
0.5
0.3
3.9
88.6
0.8
1.0
1.2
0.3
1.0
4.1
77.2
0.2
53.8
0.2
0.5
0.5
1.0
2.4
0.1
1.5
0.5
798
479
509
1028
1469
615
95.1
0.8
0.4
Banking, Housing, and Urban Affairs
0.2
82.5
0.7
Commerce, Science, and Transportation
0.2
75.0
Energy and Natural Resources
0.7
0.4
Environment and Public Works
0.9
0.3
Finance
1.3
0.5
Governmental Affairs
0.7
Judiciary
0.4
Labor and Human Resources
0.2
Other
0.2
1.4
Total number of bills
453
366
14.5
280
Transportation
Energy and Natural Resources
0.4
Agriculture, Nutrition, and Forestry
Committees
Crime
0.2
Communications
6.9
Banking and Finance
0.2
Agriculture
Employment and Labor
Table 4. Issues and committee referrals
3.5
2.0
1.0
68.6
Notes: Cell entries are percentage of all bills for an issue referred to the committee. Bold face indicates
primary or shared jurisdiction. Data for Labor and Human Resources include referrals to its successor
th
th
committee Health, Education, Labor, and Pensions in the 105 and 106 Congresses.
36
Table 5. Analysis of bill sponsorship for crime, employment, and health
37
Constituency
State Crime Rate
State Unemployment
State Uninsured
State Govt Health Care
Health Services
Econ. Size
Econ. Concentration
Ideology
Extreme Liberal
Extreme Conservative
National Conditions
U.S. Crime Rate
U.S. Unemployment
U.S. Uninsured
U.S. Govt Health Care
Party
Democrat
Majority x Dem
Majority x Rep
Committee
Member
x Majority x Dem
x Majority x Rep
Sub leader
x Chair x Dem
x Chair x Rep
Full leader
x Chair x Dem
x Chair x Rep
First Diff.
Constant
Dispersion Parameter
Baseline Expected Bills
Log Likelihood
N
* p < .05, ** p < .01, *** p < .001
-0.10
Crime
Coeff.
S.E.
First Diff.
Employment
Coeff.
S.E.
0.01
0.02 (0.06)
First Diff.
Health
Coeff.
S.E.
0.01
0.01
0.17
0.06
-3.06
(0.02)
(0.01)
(0.05) **
(0.06)
(3.82)
-0.01 (0.01)
0.56
0.01
0.44 (0.06) ***
0.37 (3.68)
0.10
-0.11
0.22 (0.06) ***
-20.23 (4.59) ***
0.04
0.05
0.36
0.10
-0.07
0.16
0.00
0.16 (0.17)
0.00 (0.16)
0.41
-0.05
0.74 (0.21) ***
-0.13 (0.19)
0.82
-0.87
0.45 (0.17) **
-0.91 (0.17) ***
-0.12
-0.02 (0.02)
0.14
-0.30
0.12 (0.11)
-0.23 (0.07) **
0.04
0.10 (0.11)
-0.20
-0.18
-0.28
-0.24 (0.27)
-0.20 (0.24)
-0.35 (0.24)
-0.06
-0.02
0.08
-0.16 (0.30)
-0.05 (0.26)
0.18 (0.27)
-0.14
-0.86
0.42
-0.10 (0.24)
-0.89 (0.24) ***
0.25 (0.22)
1.59
0.88
0.17
-0.01
-0.60
0.28
4.15
0.08
0.23
0.98
0.66
0.16
-0.01
-1.02
0.26
1.68
0.08
0.22
0.97
-0.12
-0.02
0.16
0.95
0.18
0.46
0.43
0.07
1.26
-0.39
-0.06
0.35
1.25
0.39
0.79
0.75
0.18
0.46
1.15
0.15
-0.50
2.62
0.26
2.72
1.08
0.05
0.28
0.58
0.10
-0.42
1.03
0.16
1.05
0.56
0.03
(0.30) **
(0.45)
(0.45)
(0.35)
(0.59)
(0.53)
(0.45) ***
(0.75)
(0.75)
-3.45 (1.29) **
0.69 (0.11) ***
0.95
-824.51
594
(0.24) ***
(0.38)
(0.37)
(0.43)
(0.61) *
(0.86)
(0.43)
(0.71)
(0.76)
-0.97 (1.11)
0.59 (0.15) ***
0.38
-650.7
594
(0.19)
(0.32)
(0.29)
(0.30)
(0.46) *
(0.50)
(0.34) **
(0.57)
(0.60)
3.12 (1.80)
0.85 (0.10) ***
1.45
-953.83
594
Table 6. Analysis of bill sponsorship for agriculture, banking, and communications
Agriculture
First Diff.
Coeff.
S.E.
38
Constituency
Farming
Financial Services
Communications
Econ. Size
Econ. Concentration
Ideology
Extreme Liberal
Extreme Conservative
Party
Democrat
Majority x Dem
Majority x Rep
Committee
Member
x Majority x Dem
x Majority x Rep
Sub leader
x Chair x Dem
x Chair x Rep
Full leader
x Chair x Dem
x Chair x Rep
Constant
Dispersion Parameter
Baseline Expected Bills
Log Likelihood
N
* p < .05, ** p < .01, *** p < .001
0.26
First Diff.
Banking
Coeff.
S.E.
-0.01
-0.01 (0.02)
0.02
0.01
0.06 (0.08)
0.78 (4.87)
Communications
First Diff.
Coeff.
S.E.
0.24 (0.04) ***
0.02
-0.03
0.00
0.11 (0.09)
-0.18 (0.09) *
-1.14 (5.19)
0.32 (0.22)
-0.68 (0.24) **
0.05
-0.01
0.25 (0.23)
-0.04 (0.24)
-0.23
0.55
-0.06
-0.87 (0.30) **
0.86 (0.26) ***
-0.15 (0.27)
0.06
0.02
0.07
0.29 (0.30)
0.08 (0.25)
0.31 (0.29)
1.30
-0.07
-0.04
-0.16
1.28
1.08
0.29
1.00
0.86
1.45
-0.21
-0.09
-0.50
1.43
1.31
0.54
1.26
1.15
0.09
0.06
0.21 (0.08) *
8.86 (5.42)
0.05
0.05
0.13 (0.20)
0.12 (0.21)
0.15
-0.20
0.19
-0.13
-0.07
0.41 (0.26)
-0.46 (0.22) *
-0.20 (0.25)
0.42
0.60
0.26
-0.03
-0.09
0.21
0.12
1.30
1.25
0.76
0.97
0.53
-0.07
-0.27
0.45
0.29
1.51
1.48
(0.31) *
(0.47) *
(0.47)
(0.39)
(0.59)
(0.64)
(0.57)
(0.88)
(0.86)
-5.21 (1.44) ***
0.82 (0.17) ***
0.37
-604.28
594
(0.35) ***
(0.46)
(0.53)
(0.47)
(0.66) *
(0.70)
(0.58)
(0.86)
(0.96)
0.49
-0.08
-0.07
-0.07
2.56
2.42
0.38
0.29
0.82
-1.67 (1.09)
0.91 (0.21) ***
0.04
0.40
-524
594
1.29
-0.59
-0.49
-0.48
2.68
2.63
1.10
0.93
1.68
(0.27) ***
(0.45)
(0.45)
(0.73)
(1.01) **
(1.06) *
(0.63)
(0.93)
(0.91)
0.20 (1.13)
0.82 (0.24) ***
0.18
-459.97
594
Table 7. Analysis of bill sponsorship for energy, trade, and transportation
First Diff.
39
Constituency
Natural Resources
Utilities
Farming
Manufacturing
Transportation
Econ. Size
Econ. Concentration
Ideology
Extreme Liberal
Extreme Conservative
Party
Democrat
Majority x Dem
Majority x Rep
Committee
Member
x Majority x Dem
x Majority x Rep
Sub leader
x Chair x Dem
x Chair x Rep
Full leader
x Chair x Dem
x Chair x Rep
Constant
Dispersion Parameter
Baseline Expected Bills
Log Likelihood
N
* p < .05, ** p < .01, *** p < .001
0.01
-0.03
Energy
Coeff.
S.E.
First Diff.
Trade
Coeff.
S.E.
Transportation
First Diff.
Coeff.
S.E.
0.00 (0.01)
-0.05 (0.06)
-0.28
0.34
-0.11 (0.04) **
0.03 (0.01) **
-0.03
-0.05
-0.05 (0.06)
-5.57 (3.76)
0.74
-0.06
0.42 (0.07) ***
-2.54 (4.99)
-0.03
0.14
-0.10
-0.03 (0.06)
0.15 (0.06) *
-7.29 (3.66) *
0.17
-0.18
0.28 (0.17)
-0.42 (0.18) *
-0.37
0.74
-0.32 (0.19)
0.44 (0.19) *
0.08
-0.27
0.09 (0.17)
-0.39 (0.16) *
-0.13
0.14
-0.06
-0.29 (0.22)
0.24 (0.19)
-0.11 (0.21)
-0.20
0.84
-0.50
-0.16 (0.25)
0.49 (0.20) *
-0.46 (0.21) *
-0.26
0.12
-0.04
-0.37 (0.20)
0.13 (0.18)
-0.05 (0.18)
0.83
-0.03
0.06
0.15
0.60
0.53
1.48
0.91
0.26
0.94
-0.05
0.10
0.24
0.76
0.70
1.33
1.00
0.41
5.00
-0.16
-0.50
1.12
0.24
-0.72
-0.80
0.15
32.58
1.55
-0.12
-0.47
0.61
0.16
-0.77
-0.90
0.11
3.23
1.16
0.15
-0.10
0.53
0.86
0.05
1.11
0.44
1.69
0.88
0.17
-0.13
0.49
0.71
0.06
0.85
0.43
1.11
(0.26) ***
(0.41)
(0.39)
(0.32)
(0.49)
(0.51)
(0.41) **
(0.64)
(0.67)
0.90 (0.94)
0.40 (0.12) ***
0.53
-646.78
594
(0.25) ***
(0.40)
(0.41)
(0.69)
(1.11)
(1.15)
(0.71)
(1.10)
(1.22) **
-4.50 (1.27) ***
1.66 (0.15) ***
1.34
-1073.54
594
(0.22) ***
(0.36)
(0.35)
(0.33)
(0.52)
(0.57)
(0.43) *
(0.69)
(0.68)
-0.63 (0.88)
0.56 (0.12) ***
0.82
-755.6
594
Table 8. Summary of significant effects on issue attention
Trade
Committee
Health
Empl
--------Finance--------
Comm
Trans
-------Commerce------
Ag
Banking
Crime
Energy
Ag
Banking
Judiciary
Energy
----------Labor---------Constituency
Policy
Industry
X
General
X
X
X
Ideology
X
X
Party
X
X
National Conditions
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Committee
Membership
X
X
X
X
X
Leadership
X
X
X
X
X
Table 9. Bill sponsorship before and after committee transfers
Transfer To
Transfer From
Type of Issue
Before
After
Difference
Before
After
Difference
Broad Interest
0.35
2.36
2.01*
1.80
2.27
0.47
(60)
(53)
(64)
(45)
1.20
1.74
2.03
1.59
(75)
(68)
(74)
(118)
0.82
2.01
1.92
1.78
(135)
(121)
(138)
(163)
Economic Interest
All Issues
0.54
1.19*
Cell entries in the before and after columns are average numbers of bills.
Parentheses indicate the number of member-congress-issue observations.
* Difference in means test with unequal variance is significant at the 5% level.
40
-0.43
-0.14