Sustainability and the Rebound Effect
Liang Fan
International Division
Social Sciences Academic Press
Chinese Academy of Social Sciences
1.
Prelude
China's rapid economic growth in recent decades has brought about a spectacular
rise in the country's average material standard of living, with significant consequences
for the environment both in China and beyond. The country's appetite for natural
resources is vast and growing, so are the amounts of waste the Chinese economy
generates. On an extended interpretation of Lester Brown's question "who will feed
China", it is no longer about food only, but all forms of natural resources. We must
also add the question: where is all her waste discharge going to go? There are good
reasons for wanting to check the expansion of the Chinese economy's overall pressure
on the environment, that is, its aggregate ecological footprint. We all have an interest
in the environmental sustainability of the Chinese economy.
Doing this won’t be easy, of course, and we have some ideas as to how to go
about it, though some of them are surely better than others. I will begin by identifying
one fundamental strategy that I think is a good idea, indeed a very good idea. It is so
fundamental, and so good, that whatever specific measures we take to try to achieve
environmental sustainability, they should be consistent with it. The strategy is also a
very simple idea: so say you want to solve a problem, identify all the factors causally
relevant to its existence, and work on each of them to optimize your outcome.
Applying this strategy to the task at hand, we get, straightforwardly: identify all the
factors on which any population's ecological footprint depends, and work on each of
them. The core feature of this strategy is that it is supposed to be thorough,
comprehensive, and integrated, leaving no aspect of a problem unaddressed.
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For example, the rate of gun violence in a population is a function of, i.e.,
causally linked to, many factors, including, among others, the rate of gun ownership,
the severity of the criminal code, the rate of unemployment, average level of
schooling, degree of ethnic/class tension (or, conversely, that of social harmony). So if
you want to reduce gun violence, ideally, we should try to address all these things, and
preferably according to their relative importance in the causal mix. Take, in another
example, body weight management. Body weight is a multiple determined by
different factors, some genetic, some lifestyle, and some environmental. So in order to
achieve one’s weight management objectives, one should, ideally, consider what one
can do in each of these areas. An exclusive focus on a subset of the relevant factors
would either lead to suboptimal outcomes, or, worse, turn out to be counterproductive.
Causal relevance comes in different degrees and modes, and causes can be more
or less direct in relation to an effect. Indirect causes must be, by definition, connected
to the effect through direct ones, and among indirect causes, some are more indirect
than others. Depending on the circumstances, in some cases, the further upstream
along the causal chain intervention is applied, the more thoroughly a problem is
treated. For example, if depression makes one overeat; which then lead one to gain
weight, then depression is in this case an indirect cause of weight gain. And if the
same person happens to carry a gene that predisposes him to depression (but none, let
us stipulate, to obesity), then his genetic make-up would be a still more indirect cause
of his weight gain than the depression itself. This individual's efforts to deal with his
weight problem may yield more sustained results if they targeted not just his
overeating but also his depression.
So what are the things on which any population’s aggregate environmental impact
depend on? In 1971, the American biologist Paul Ehrlich and the American physicist
John Holdren (now science advisor to President Barack Obama) formulated a theorem
that purports to capture exhaustively the determinants of the aggregate environmental
impact of any population. The theorem is 'I = P·F'. It means that the aggregate
environmental impact of a population ('I') is the product of the size of the population
('P') and per capita environmental impact ('F'). Their article was published in the
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March 26th issue of the journal Science (published by AAAS, the American
Association for the Advancement of Science).
A few years later, largely in response to criticisms by the biologist Barry
Commoner (made at various places in his many books, including The Closing Circle:
Nature, Man, and Technology), the formula was modified to reflect the two factors on
which per capita environmental impact depends, namely, per capita level of
consumption (C), and the environmental impact per unit of economic output (T). This
last factor depends primarily on the productive technologies used in the economy: the
more resource efficient they are (the cleaner they are), the less the environmental
impact, that is, the less resource intensive and less polluting, per unit of output thus
produced. The revised theorem “I = P·C·T”, where 'C' is per capita consumption and
'T' is environmental impact per unit of economic consumption or output eventually
permutated into its current form: I = P·A·T, where 'A' stands for “affluence”, of which
the level of per capita consumption of economic output is a rough measure.
According to our “very good idea” strategy, to ease or otherwise manage a
population's total pressure on the environment, its population size, its per capita
economic consumption of economic output, and the environmental impact per unit of
output must all be subject to some kind of control. In particular, assuming zero
population growth, per capita environmental impact depends on both per capita
consumption and how resource intensive and polluting each unit of output consumed
is, and increases in the former would cancel out reductions in the latter. In other words,
measures to contain changes in each factor would be in individually necessary but
insufficient for our overall purpose of achieving sustainability. This has been very
schematic, but I hope it is reasonably clear.
2.
Rebound Effects
2.1 General introduction
The IPAT formula is meant to be a theorem, that is, it is truth by definition.
3
Moreover, its truth does not depend on or require the three dependent variables to be
mutually independent, which they certainly are not. Income level can influence
reproductive choices and fertility rates in measurable yet complicated ways. Per capita
economic consumption and the resource efficiency of productive technologies also
exert mutual influence. And I suggest that at least in one direction, from resource
efficiency to aggregate output, the influence may illustrate a phenomenon called
"rebound effects", which is when improvements in efficiency are followed by
increases in the production and/or the demand for the relevant output. If the rebound
effect (or “effects”) is/are real, it could complicate efforts to contain the aggregate
ecological impact of any population, that is, even if we assume the best scenario for
population. Specifically, it would mean the need to place limits on the aggregate scale
of material and energy consumption, in addition to the need to improve resource and
energy use efficiency. At least this is what I want to argue in this paper.
First, I will give a brief account of the phenomenon as it is now understood, by
summarizing some of the main findings regarding it in the area in which it has been
most intensely studied, namely, energy economics. I will try to show that rebound
effects are a generic and pervasive phenomenon observable in many areas of human
life. Then I take up the question of why the phenomenon exists, and what might be
done about it. Lastly, I will consider the possible implications the rebound effects
have for efforts to achieve environmental sustainability. I will argue that “technical
fixes” meant exclusively to improve resource use efficiency should be supplemented
or otherwise accompanied by (independent) measures meant to contain the upward
shift in the aggregate scale of consumption. Without these other measures, we would
only be buying ourselves more time before eventually running up against ecological
overshoot and facing the associated economic catastrophes and social traumas.
The British economist William Stanley Jevons has been credited for being the
first to formally recognize the phenomenon, as early as 1865, to which the eponymous
name "Jevons' Paradox" was given. Now generally, we call something a paradox, or
say that something is paradoxical, when we perceive a certain contradiction or
internal inconsistency, or even logical incoherence, or something that is expected in
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some important way in it. For example, when the actual consequence of something is
the opposite of, or just very different from what was intended or expected, we tend to
deploy the concept of paradox. Being paradoxical, it seems, is not an intrinsic
property of facts of the world, but a relational or extrinsic one: something is
paradoxical to somebody, and relative to particular expectations or preconceptions
that person has about something. To “cure” a particular paradox, the subject in
question simply needs to understand how and why she was erroneous about the
relevant facts. More colloquially, if a paradox is something that seems to “make no
sense” to somebody, then that person can rid herself of this condition by trying to
make sense of it, and chances are, there would be sense to be made. (See opening of
ch.9 by Roger Levett in Sorrell)
Today, economists know the phenomenon under the less colorful name of the
'Khazzoom-Brookes (K-B) postulate', after two contemporary economists, Len
Brookes and Daniel Khazzoom. The postulate states that: "with fixed real energy
prices, energy-efficiency gains will increase energy consumption above what it would
be without those gains" (Sorrell, 8, citing Saunders, 1992). Academic interests in the
rebound effects have been most pronounced among energy economists, but they are
more so now than ever against the backdrop of anthropogenic global climate change.
The most favored approach by industries and governments to mitigating the impact of
climate change has been to encourage technological improvements that increase
energy efficiency. But whether this is sufficient (or, as we will see later, even
necessary) depends on whether such improvements are susceptible to the rebound
effects. If so, then not only might technological improvements alone deliver less total
energy savings than we want, worse, they might defeat the purpose. The policy
implications of the rebound effect are, therefore, profound and possibly unsettling.
To appreciate what it is that may have seemed paradoxical or unexpected to some
about the rebound effect, and just what exactly has rebounded where, when, how, and
by how much, we need to be clear about the point of reference, that is, what has been
expected to happen to total energy demand following improvements in efficiency. For
any input-output conversion system, the total input needed to produce a certain level
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of output depends on: (1) the number of units of output and, (2) the amount of input
needed to produce each unit of output. According to “simple engineering
calculations,” (Sorrell, 4) if we hold the value of either (1) or (2) constant, the value
of their product would (1) change in the same direction and (2) by the same
magnitude (i.e., proportionately) as the change in the value of the other variable. If the
values of both variables change together, the directions and the magnitudes of the
changes would determine how the value of their product changes. So if demand for an
output remains unchanged, an energy efficiency improvement in its production should
lead to a total energy savings identical to the magnitude of the efficiency
improvement.
This ideal scenario must be the reference against which increases (the “rebound”)
in the production and/or consumption of an energy-using output subsequent to an
efficiency increase, which reduces the total energy savings, might have seemed to
some to be unexpected. Of course, since the size of the rebound can vary greatly from
case to case, so would the amount of reduction in total energy savings. The larger the
rebound, the steeper the reduction, and in the worst case, the efficiency gain would
“backfire” if it is cancelled out or neutralized by the subsequent increase in output
production and/or consumption. In an important sense, studies of rebound effects are
really studies of the failure of the assumption that the production and/or demand for
an output would remain unchanged despite or independent of efficiency
improvements.
A close look at the meaning of some of the key concepts might be a good place to
begin. First consider “efficiency”, which means or refers to the ratio between input
and output for any input-output conversion system. The rate of efficiency for any
particular conversion system is a number that is the function of two other numbers,
one for output and one for input. When we say that some conversion processes or
system is efficient, we are not saying that it has a rate of efficiency, which all
conversion systems do, but giving a favorable evaluation of its rate of efficiency
because it meets or exceeds certain expectation we have. Similarly, when we say that
something is inefficient, we mean that the rate of efficiency falls short of some
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expectation or statistical norm, say.
The rate of efficiency improves for a conversions system when it is able to “do
more with less”, that is, when its input-output ratio is reduced. However, an efficiency
improvement itself does not mean that the system would either produce more total
output or use less total input than before. How much output a system produces and
how much input it consumes after an efficiency improvement depends on what the
relevant agents decide to do. If my reading efficiency has gone from 1 page per
minute to 2 pages per minute because I have learned speed-reading, how much I now
decide to read, and how much time I decide to spend on reading now as compared
with before depend on what I want - with my time, with what I can learn from reading,
and indeed, with my life – and not on the efficiency improvement itself. The ability to
do more with less does not determine how that ability is used. In other words,
efficiency improvements can never be a goal in its own right, but is only a mere
means for some other ends, either more output of some sort, or less input of some sort,
or some combination thereof. In daily discourse, we do not usually take the trouble to
state explicitly what those other ends are, and talk as though we believed that greater
efficiency is a good in itself, but that is because we often take it for granted most
people share these tacit assumptions.
The idea of “saving”, frequently associated with that efficiency improvement, is
similarly ambiguous. The familiar marketing mantra “The more you spend the more
you save” illustrates this well. Taken at face value, the statement seems outright
incoherent: how could it be that the more you spend the less you spend? The
construction is a verbal trickery that works by omitting crucial qualifiers: what it
means to say is that the more one spends in total the more one saves in terms of the
percentage of total expenditure. In other words, as total spending increases, so does
the efficiency of your money. In still other words, there is economy of scale when it
comes to spending money, and to get more economy, you need to increase the scale.
Of course, how a consumer actually behaves depends on whether she is trying to
minimize total expenditure or to maximize the efficiency of her money. What this
jingle shows is not only can the logic of the rebound effect be turned around and used
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for the very purpose of increasing aggregate spending but also how irrational it is to
increase total spending in order to achieve ever greater money efficiency.
2.2
How does it happen and why?
The question of the nature of the connection between efficiency improvement and
subsequent increases in total consumption has been hotly debated. It has often been
noted in the literature that the empirical association is no evidence for causation. This
is true as far as it goes, moreover, the foregoing analysis suggests yet another,
independent reason why we should be careful with claims of causal connection
between the two events: if efficiency improvement is not a terminal end in itself, but a
mere instrument, how can it, as an instrument, have qualitatively determinate (though
quantitatively indeterminate) impact on what it is actually used for? How can
efficiency improvement cause, by itself, changes in the number of units of the relevant
output produced and/or consumed (or input) in either direction? More dramatically
perhaps, why would a better hammer make me (want to) put more nails in the wall?
(Surely it might, but the issue is why.) To work my way toward an answer, I want to
(1) review some of the basic findings about the rebound effects in energy economics,
and (2) show that rebound effects are a generic and pervasive phenomenon observable
in many areas of human behavior. I want then to suggest that there are common
underlying dynamics to all these instances of the rebound effect, whose identification
is crucial to answering these questions.
Empirical studies of the rebound effects in energy consumption requires clear
definition or delimitation of a number of factors, including how "energy efficiency" is
conceived of and measured, time frame, scope or system boundary, and underlying
mechanism (in the final analysis, we are interested in the long run, the entire economy
for each country, and really for the world, and all possible psychological mechanism,
the lack of the notion of sufficiency to function as a ceiling). As already noted, the
rate of efficiency for any conversion system is the amount of input needed to produce
each unit of output. Energy efficiency, more specifically, refers to "the ratio of useful
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outputs to energy inputs for a system" (Sorrell, 11). But since what constitutes “useful
outputs" for any given system can be understood thermodynamically, physically, or
economically, corresponding to measurement in terms of heat content, physical
quantity or monetary value, respectively, how "energy efficiency" should be
understood is context-dependent. The unit of analysis might be households, firms,
industrial sectors, national economies, or the global economic system. And one may
be interested in longer or shorter periods of time.
As concerning the mechanisms (configurations of causal pathways) of how the
rebound happens, direct rebound effects have been distinguished from indirect ones.
Together, they make up economy-wide rebound effects. For consumers, direct
rebound effects are further divided into substitution effects and income effects. The
former takes place when consumers substitute the same goods or services for others,
and income effect is when the increase in real income that results from the reduced
expenditure on the relevant output is spent on other things. For producers, an
analogous conceptual distinction is made, albeit with slight terminological alterations
(e.g., the equivalent of “income effect” for consumers would be “output effect” for
producers). Indirect rebound effects, on the other hand, are further divided into
“secondary effects” and “embodied energy effect”. Secondary effects include a wide
range of changes in demands for economic output (for consumers) or structural
changes to industrial production (for industries), and lastly, embodied energy effect
results from the additional energy required to physically implement the more energyefficient technology.
The embodied energy rebound effect differs from the other types in two important
respects. First, it happens for purely engineering or technical reasons. That is, it is a
technical imperative and as such independent of the decisions by either the producers
or the consumers concerning how much of what to produce and to consume. Second,
unlike the other type of rebound effects, which are responses either to the realization
of the efficiency improvement or to anticipation for its realization, the embodied
energy rebound effect is itself a necessary precondition for the realization of the
efficiency improvement. In other words, it necessarily takes additional energy to
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install more energy-efficient technologies at scale, but once this has been done,
decisions about how much output to produce and to consume are logically
independent of engineering considerations. These are the decisions I am most
interested in here.
What all the other types of rebound effects, including substitution effects, income
or output effects, and secondary effects, have in common is that they seem to reveal a
(pre-existing) condition on the part of the system in question, a preference for the
production or consumption of more output (the same or total). The rebound might be
seen as a "clinical symptom" of this background, standing condition of the system. We
can understand this preference for more as a disposition, i.e., a “tendency” or
“propensity”. The notion of disposition is usually defined counterfactually: it is a
property in virtue of which what possesses it would behave in a certain way under
specific types of conditions. The definition is counterfactual in the sense that the
possession of a dispositional property does not depend on or require the antecedent of
the counterfactual claim ever being true. For example, if something has the
dispositional property of being soluble (i.e., has the property of solubility), it would
dissolve in water, even if it never comes near any. The elasticity of a rubber band is a
dispositional property, and a rubber band that is never actually stretched (before it
decays, let’s stipulate) is elastic nonetheless. A brave person is brave (where “bravery”,
as a character trait, is treated as a dispositional property of an individual) even if she
never encounters a dangerous situation. That we may never be certain if something
has a particular dispositional property is an epistemological problem, not a conceptual
one.
If we think of the preference for more output as a disposition of a conversion
system, the rebound would be treated as the way in which the system behaves under
the condition of improvement in the input-output ratio. What such an improvement
does is to relax by an increment an elastic constraint on total output. In other words, a
system with this preference is always in a state of being prepared to increase total
output, and that when it does not do so it is only because it could not afford to under
the current budget constraints with respect to input. And when the constraints are
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eased, which is when there is an improvement in the input-output ratio, the system
responds by increasing total output by some margin. Each occurrence of rebound,
therefore, can be explained by reference to the fulfillment of two conditions, one
external and one internal to the system: (1) the pre-existence in the system of the
dispositional property of a preference for more output (this is internal to the system),
and (2) an increase in the amount of output each unit of input is able to yield (this is
an external condition, a “trigger” to the system rebound). The two conditions are
individually necessary but insufficient, and jointly sufficient for the rebound to take
place.
Recall that I had granted earlier that the empirical association between efficiency
gain and increases in production or consumption of output is no evidence for
causation. I said we needed to be careful with causal claims, but did not suggest that
the relation here is not a causal one. So the key question is how efficiency
improvement can lead to particular uses that can be made of it and if we were to
understand this in causal term, how. The critical issue, I think, is what conception of
“causing” is used. What both the denial of and skepticism about a causal connection
seem to assume is that the efficiency improvement has to be either the sole cause or
the most important one among several. But what I have tried to show is that not only
is the pre-existing preference for more causally (and thus explanatorily) relevant to
understanding the rebound, it is very important. Whether it is more or less important
than the efficiency improvement is, however, a much harder question to answer. So
asking whether efficiency gains cause production expansion and demand increase is a
little like asking whether a pencil falling to the ground is caused by my letting go of it.
A sound explanation for how the pencil behaves when I let it go should cite at least
two things - the law of gravity, and my withdrawing of support for it – though not
necessarily in that order (since, here again, it is hard to say if the two can be ranked in
terms of their causal or explanatory importance). At any rate, my support for the
pencil might be seen as an impediment to its (free) falling, something the pencil is
naturally inclined to do, and when the impediment is removed, the pencil behaves as it
naturally would.
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Analogously, an input budget constitutes a constraint on the increase in the
corresponding output. But the constraint is elastic so long as the input-out ratio can
improve. Each improvement would free up some room for output to increase. In this
sense, it would not be wrong to say that efficiency improvement, as a form of easing
of a constraint, causes the subsequent output increase, so long as it is understood that
by this is not meant that no other causal or explanatory factors are involved. So far as
the rebound effect is concerned, it is the efficiency improvement and the pre-existing
preference for the production and/or consumption of more output that jointly produce
the rebound.
2.3
The rebound effect as a pervasive phenomenon
While the rebound effect in energy consumption has received the most
scholarly attention, it is really quite a pervasive phenomenon observable in a wide
range of areas of human behavior. I will use three examples to show this: (1)
“healthy” food and eating habit; (2) ‘low tar’ cigarettes and smoking habits; (3) paper
recycling and paper consumption.
The original intent behind the introduction of healthy food, such as “low-fat”,
"sugar-free", "low-calorie" versions of conventional foods in the U.S. Food market
was to help consumers reduce their consumption of certain things excess consumption
of which has been identified as a health risk, by leading to, most prominently, weight
gain. However, it has been documented that so far at least, the wide availability of
these foods, at least in the US, has done little to mitigate the problems of overweight
and obesity, which have continued to worsen. What many studies have shown is that
this can in part be accounted for by the tendency for the consumption of what is
unhealthy in excess amount to rebound in response to “healthy food”. There are
different ways in which such rebound might take place. For example, the frequent
exposure to messages encouraging choosing healthy food while rejecting "unhealthy"
ones seems to have some kind of “subliminal influence” on some people by
strengthening their desire for the latter, inducing them to eat more of it. But the actual
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consumption of “healthy food” may also rebound. People might either give
themselves the license to eat more servings of healthy foods than they would servings
of regular foods, or they do so unintentionally because it takes more servings of health
foods to reach satiety. In either case, the result is a reduction in the amount of
reduction in the consumption of what it is (say, fat or calorie) one was trying to
consume less of in the first place.
There is no shortage of anecdotal evidence that supports the existence of these
phenomena. It is not uncommon for people to eat more low-fat cookies than they
would regular cookies. And if the margin of increase is large enough, the total number
of fat or calories one ends up consuming would exceed how much one would
consume by eating regular foods. Indeed, this is a matter of “simple engineering
calculation”, as it were. And insofar as total calorie intake matters as much if not more
than the compositional structure of calorie source (fat, protein, dietary fiber,
carbohydrates) to body weight and health, a rebound in total calorie intake through
increases in the number of servings consumed of foods containing less of some
specific target element per unit of serving can be reasonably expected to help worsen
the problems to which the introduction of healthy food options was intended to be a
(partial) solution.
These are but two of possible mechanisms by which healthy food - either
advocacy for its consumption, or its mere availability, or the actual consumption of
it – can rebound, leading to shifts in eating habits that may in the end prove to hurt
rather than benefit one’s health. The shared logic among these different mechanisms is
one of compensation for actual or perceived deprivation. As we saw, this can take
place at either the psychological or the physiological level. Psychologically, one
might compensate for the strain of doing what one “should” by indulging in doing
what one prefers (instead), that is, doing more of the latter than one might otherwise
have done. Physiologically, since for whatever reason low-fat foods, say, often
(though not always) generates less gastronomical satisfaction per serving than regular
foods, people end up eating a larger number of servings to derive the same level of
utility. And again, not dissimilar to energy consumption, we might say that these
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rebounds in eating habits reflect the pre-existence in many of us of a preference for
more food, more tasty food and, in rather abstract terms, more feeling of satisfaction
from eating in general. So long as this condition holds, the availability of foods with
reduced health risk (real or perceived) per unit of serving cannot be expected to do
much to help us achieve good health through dietary means.
Certain ways of “packaging” healthy food has also been shown to have a
substitution rebound effect. For example, it has been noted that, when it comes to
restaurant eating, consumers who choose to patronize eateries that claim to offer
healthy food choices tend not only to underestimate the caloric value of main dishes,
but also to substitute some of the main dishes they forego with side dishes, drinks, or
desserts, which can pack significant combined caloric value.1 The result is that
consumers may end up taking in more calories eating at these restaurants than they
would at restaurants that don’t make health claims.
Much like the failure of genuine public health improvements to materialize,
especially in respect of the incidence of weight-related chronic diseases, after the
introduction and popularization of healthy foods, the introduction and the
popularization of the so-called “low tar” cigarettes have reduced neither smoking nor
the harmful health effects of smoking. What studies on the impact of this type of
tobacco products on smoking habits and nicotine intake have shown is that, among
other things, smokers tend to compensate for the reduced nicotine uptake per puff –
either real or perceived – by “inhaling more deeply; taking larger, more rapid, or more
frequent puffs; or by increasing the number of cigarettes smoked per day.”2 The
implicit reference by which these comparisons are made is of course the smoking of
regular cigarettes. While researchers do not tend to speculate on the intentions of
industries that have offered these “less-harm-per-unit-of-serving” alternatives of their
products, the rebound effects that have been observed certainly raise some
uncomfortable questions. Here the issue, it seems, is not whether the rebound effect is
1
Pierre Chandon and Brian Wansink, “The Biasing Health Halos of Fast-Food Restaurant Health
Claims: Lower Calorie Estimates and Higher Side-Dish Consumption Intentions,” Journal of Consumer
Research, Vol. 34, October 2007.
2
“Risks Associated with Smoking Cigarettes with Low Machine-Measured Yields of Tar and Nicotine”,
National Cancer Institute (NCI), 2001.
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real or substantial, but that it is precisely because it is, and that some know this to be
the case, that it may be used to achieve possibly perverse commercial ends. In fact,
where and when it is effective, it is effective in two separate but related senses: in
inducing a rebound and in projecting an image of themselves as responsible
corporations that are trying to do what is best for their customers.
Yet another area in which rebound has been noticed relates to the rise of recycling
and its impact on material and resource demand. First, recycling is a kind of
efficiency improvement. When we recycle, we reclaim materials from wastes to be
reused as input in the production of either the same or other types of products. So
when we recycle, and the more we recycle, the greater the material use efficiency for
the types of material being reclaimed and for the entire production system utilizing
those types of material, in one way or another, and at one point or another in the
system’s industrial metabolic process. All other things being equal, recycling
promotes material conservation. But all other things are not equal, thanks in part to
the rebound effect. In the United States, for example, paper recycling has not led to a
reduction in the aggregate demand either for paper products or for timber. The same is
true for other OECD countries.
Unlike other kinds of efficiency improvements, however, paper recycling requires
the participation of the end users of paper products, the consumers. Unless they sort
their garbage, there would be nothing that gets collected and sent to recycling plants
for further processing. And unlike, say, driving a more fuel-efficient car, which can
translate into economic payoff for the consumer in the form of reduced gas
expenditure (and rise in real income), except in cases where an incentive scheme has
been put in place to encourage recycling, doing it often does not pay, financially.
Therefore, to the extent participating in recycling rebounds in the form of higher
demand for paper products, this is likely attributable to changes in the level of
psychological expenditure associated with paper consumption.
An explanation might go something like this. Once consumers are informed about
the adverse environmental impact of the paper industry, it would likely generate
certain moral unease on their part about paper use and disposal. This unease amounts
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to a kind of psychological cost associated with paper use and disposal. This added
cost (added, that is, to the economic cost) we could surmise, might by itself have
some effect, however mild, toward placing restrictions on one’s paper use (assuming,
though perhaps not wildly, that many people want to do what is right by the
environment). However, once the environmental benefits of recycling are also known,
and recycling becomes an option, consumers would likely see paper use and
disposable as less environmentally harmful, and feel less moral ease about them. This
reduces the psychological cost per unit of paper used and disposed of, which then
relaxes whatever constraints consumers may have placed on themselves in the use of
paper. In other words, now that they experience less guilt per unit of paper used and
dispose of, they may increase their self-imposed “quota” for paper use and disposal
without having to suffer a proportionate increase in the aggregate amount of guilt
associated with these behavior.
Are these three examples of rebound effect amenable to the type of explanation I
gave for energy consumption? I think so. In the case of healthy food and eating habit,
and as I already hinted earlier, the increase in the number of servings and total number
of calories consumed in response either to the bombardment of messages about
healthy eating or the actual consumption of healthy food is explained by reference to
the fulfillment of two conditions: (1) the pre-existence in many of us of a preference
for more eating of more tasty food, and/or more feeling of satisfaction from eating,
and (2) a reduction – either real or perceived – in the amount of harm to health per
unit of food consumed. In the case of ‘low tar’ cigarettes and smoking, intensified
smoking and increases in nicotine intake in response to the choice of these allegedly
“less harmful” products take place because of (1) the pre-existence in many smokers
for more smoking and/or the pleasurable sensation derived from smoking, and (2) a
reduction – either real or perceived – in the amount of harm-to-health per puff (or per
cigarette, or per whatever other unit that might be used for measuring nicotine
delivery efficiency). And lastly, in the case of paper recycling and paper use and
disposal, the rebound can be accounted for by (1) the pre-existence in many paper
recyclers a preference for more opportunities to use paper and greater freedom to
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dispose of it, and (2) a reduction – either real or perceived – in the amount of moral
burden per unit of paper used and disposed of.
The upshot is that if the objective is to reduce the consumption of or demand for
something at the aggregate level, that is, at the level of total scale, then efforts to
improve efficiency must be supplemented by independent measures that are designed
specifically to keep the growth of total scale in check. As many health experts have
been arguing, largely in response to the waves of diet fads come and gone, to maintain
a healthy weight, “portion control” is the way to go. But portion control just is scale
management. What it prescribes is that, if what you want is good health, and for your
diet to help you achieve it, then whatever the fat-, sugar-, carbohydrate-density of
what you choose to eat, don’t eat too much of any of them, and certainly don’t eat too
much in total amount. Again, if you must smoke, yet wish to minimize the health risks
of this intrinsically harmful habit, then, whatever type of cigarettes you choose,
smoking less of it the better (or the less bad). And, if an individual really wants to do
right by the environment by keeping the ecological footprint of one's paper
consumption small, then, whether or not recycling is an option, and whatever kind of
paper one must use, keep the total scale of use and disposal under control.
I mean for these recommendations to illustrate one strategy that might be used to
mitigate the rebound effect, which is, of course, not our ultimate goal any more than
improving efficiency is. Our real goal is to contain the increase in the aggregate scale
of something that is naturally inclined to grow: to keep total calorie intake consistent
with the requirements of health, to keep a smoker's nicotine intake to a minimum, and
to keep one's paper use and disposal no more than is necessary. We have needed to
tackle the rebound effect only because improving resource use efficiency has turned
out to be an inadequate solution to these kinds of problems.
4.
Implication for environmental sustainability
I argued earlier that to keep an economy's aggregate ecological footprint
consistent with the ecosystem's finite (though not inelastic) carrying capacity, we need
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to make sure all three factors on which aggregate ecological impact of a population
are carefully managed. It follows that in addition to controlling population growth rate,
and improving the economy’s overall resource-use efficiency, the increase in the
absolute level of per capita consumption of economic output should also be subject to
restraint. This was not so much of a “proof” for the last statement as an explanation of
the IPAT theorem. Most importantly, that explanation is valid whether the three
dependent variables in the formula are mutually independent or not. In other words,
accepting the truth of the theorem, and the problem-solving strategy outline at the
beginning of the talk would entail that one must agree that keeping per capita
consumption at a sustainable level must be part of a comprehensive strategy to
achieve environmental sustainability, whether or not per capita consumptions is
influenced in some systematic way by an economy's resource use efficiency.
But now we know better than to assume the mutual independence of the values of
these two variables. The rebound effect shows that assumption to be demonstrably
false. Significantly, this makes possible for a much stronger case for the need to
contain per capita consumption: for if this would be necessary under the false
assumption of the independence of per capita consumption from resource use
efficiency, it would be all the more so, and more urgently so given the indisputable
existence of the rebound effect. If we didn't actively try to contain the increase in per
capita consumption of economic output, improvements in resource use efficiency
would continue to push it upward, and thereby defeating out purpose of keeping the
aggregate environmental impact of a population consistent with the requirements of
environmental sustainability.
To belabor the point, if an understanding of the logic of the IPAT theorem tells us
that containing the scale of per capita (and by extension the aggregate) consumption
of economic output is necessary in addition to improving resource use efficiency, our
understanding of the logic of the rebound effects should tell us that efforts to contain
the scale of per capita (and by extension the aggregate) consumption of economic
output are urgently needed precisely because of continual improvements in resource
use efficiency.
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In a recent article about the rebound effect in the New Yorker Magazine, the
author quoted Amory Lovins, an American physicist and environmentalist, Chief
Scientist of the Rocky Mountain Institute, as saying, perhaps half facetiously, that if
Jevons' argument is correct, that is, if the rebound effect is real, then "we should
mandate inefficient equipment to save energy." The article's author went on to ponder
the question of whether this idea is really as “laughably illogic” as Lovins had
intended it to be:
“If the only motor vehicle available today were a 1920 Model T, how many miles
do you think you'd drive each year, and how far do you think you'd live from
where you work? No one's going to "mandate inefficient equipment," but, unless
we're willing to do the equivalent--say, by mandating costlier energy--increased
efficiency, as Jevons predicted, can only make our predicament worse.”
Why costlier energy? As any first-year economics student would know, we use
less of what is dear, more of what it cheap (ceteris paribus!). Costlier energy would
suppresses aggregate demand and consumption, which, of course, is precisely what
we need to do. What the idea that if we were not willing to make energy more costly
increased efficiency "can only make our predicament worse" implies, perhaps
shockingly, is that while we might have thought that efficiency improvement is
necessary but insufficient for achieving our sustainability goals, the fact may be that it
is really unnecessary because counterproductive. However, I do not want to argue the
point here (and the author of the New Yorker piece does not, perhaps wisely, say as
much either).
Of course, making consumption costlier is but one way of containing the
growth of its aggregate scale, it is an economic instrument, and it would work either
because of or despite the alleged insatiability of human wants, and the boundlessness
of the desire for goods and services of all kinds. These are fundamental precepts in
economics, basic assumptions whose truth is held to be self-evident, and they are the
reason for the pre-existing preference for the production and the consumption of more
output that I have spoken of throughout this paper. Does that mean that suppose we
could not bring ourselves, for whatever reasons, to making consuming more output
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meaningfully expensive, we would have no other way to contain the tendency for per
capita consumption to increase?
First, I contend that it is an open question whether these assumptions are true, and
if so, whether they are self-evidently so. Second, the problem now is not what the best
strategy is for containing the rise in per capita consumption; it is that few want to do it
at all. Most perhaps think the idea politically flammable and culturally distasteful, and
economically suicidal. The fear of stagnant growth has consistently trumped the fear
of ecological overshoot and collapse, which may prove, once again, that it is easier to
fear what we have seen than to fear what we have not and could not imagine. People
everywhere are being told to consume more to keep the economy growing at a brisk
pace, and to make themselves happy. And they are also told that whatever adverse
environmental impact of economic production and consumption would be more than
neutralized by better, smarter and cleaner technologies. But if the rebound effect is
real, and significant, which we have good reasons to believe that it is, then
encouraging people to consume more despite our collective nominal commitment to
environmental sustainability, is really what is laughably illogic.
Of course, I hope nobody is finding this funny, because it is not.
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