IntellectuaLDiscourse, 1994
Vol 2, No 2, I3l-144
Islamic Economics Literature:
A Bibliometric Analvsis
Sajjad ur Rehmanx
Roslina Othmans
Abstract: The study testedthe hypothesisthat Islamic economicsliterature
exhibitsthefeaturesof the BradfordianLaw of Scatteringwhileidentifyingcore
authors,pubLishers,
sourcesof literature,and countriesof origin. A databaseof
3,026 citationswascreatedwith informationabout thefour primary meosures.
Theoccurrence
countsweretabulatedanddisplayedin bibliographsas essential
instruments
hypothesis
testing.It wasfound that thehypothesis
couldnot be
for
supportedas the immatarestateof thedisciplinedid not exhibitthefeaturesof
estabLished
disciplines.Coresfor authors,publishers,sources,and countriesof
origin werealso identified.
Bibliometricsis the study of scholarly communicationpatterns in a
disciplinethrough the applicationof statisticalmethodsto a given corpus
of books, journal articles, conferencepapers, and other media output.
Citation analysis,an essentialbibliometric technique,furnishesimportant
indicatorsof scholarly communicationpatterns.Three bibliometric laws
address three quantitative dimensions and many studies have been
conductedin diverse areasof natural and social sciences.Lotka's Law
(1926) is used to predict the productivity patterns of various authors,
Zipf's Law (1933) describesword frequencyrankings,and Bradford's
Law of Scatteringdisplays the distribution of documentsin a manner to
identify core literature and establishtransition points betweenzonesof
*Sajjad ur Rehman is Professor and Head of the Library and Information
ScienceDepartment,InternationalIsiamic University Malaysia.
gRoslinaOthman is Lecturer, Departmentof Library and Information Science,
International Islamic University Malaysia.
Isr-etrtcEcottourcsLITERATURE
u32l
higher and lower utility.l These quantitativeanalysesare helpful in
designing economic information systemsand networks, improving the
efficiency of information handling processes,identifying and measuring
the deficienciesin bibliographical services,and analyzingpublishing and
communicationtrends.2
The Bradiordian Law of Scatteringis based on the premise that a
whole range of journal literature actsas a family of successivegeneratithe Law of Scatteringas:
ons of diminishingkinship.3Bradfordexplained
productivity
... if specificjournalsare arrangedin orderof decreasing
a
nucleusof
into
divided
be
they
may
given
subject,
of articleson a
groups
and
several
subject
devoted
to
the
particuiarly
more
periodicals
when
the
the
nucleus,
as
articles
number
of
the
same
or zonescontaining
be
as
will
zones
succeeding
and
nucleus
periodicals
in
the
numberof
1:n:n2.4
Bradford discoveredthat he could dividejournals into threegroups in
such a way that each group contributed about the same number of
articles.This distributionin threeroughlyequalgroups displaysa highyield zone of few sources, a moderate-yieldzone consisting of a large
number of sourcesthat give moderateproduction, and a still larger zone
with constantiydiminishing productivity. The law may well describe
such as populationamongcities, books in a library,
diversephenomena
the use of subjectheadingsto describea set of books, and many others
as well.s
A document is embeddedin the literature of the subject which is
expressedthrough referencelists, endnotes,and footnotes.A citation is
thus a linkage of a whole or part of a documentto a part or whole of the
sourcedocument.The citationsusuallyindicatethe interactionamongthe
authors and thosethey cite.6 A systematicstudy of theserelationshipsis
termed as "citation analysis." The Law of Scatteringis basedon citation
analysis. Sincethe fundamentalpurposeof researchis communication,
citation analysisbecomesa reliable instrumentfor investigatingcommunication and influencepatternsin any discipline.
Hypothesis
In the last three decades, Islamic economics has emerged as a fastdeveloping discipline that draws both on classicaland modern sources.
The body of literature so far produced,albeit in the stageof infancy,
provides a basisfor institutionalizingIslamic economicsin various areas
of application. It was consideredworthwhile to subject this body of
lNtgLr-pcrue.lDtscouRss
[133]
literatureto citation analysiswith the primary hypothesisthat the Islamic
economics literature exhibits the features of Bradfordian Law of
Scattering. A test of the hypothesis was expectedto result in the
identificationof core, moderate,and diminishingzonesof productivity
or influenceby using the measuresof authors,publishers,particular
sourcesof literature,and countriesof origin. It was also expectedthat
a pattern of diminishing returns in a hyperbolic distribution would
emergefiom the citation analysisof the literature. An analysis of the
zonesof distribution by applyingthe BradfordianLaw of Scatteringwas
also expectedto reveal scholarly communicationtrends and the stateof
maturityof the discipline.
Procedures
The English-language
literatureof Islamic economics,availablein the
library of InternationalIslamic University Malaysia, as part of its
databaseproject, was targetedfor this purpose. Publicationsof 1983-92
with a minimum of ten citations,excludingself-citationsand Ibid./Op.
cit notes,fell within the parameters
of the study.Additionalcriteriawere
also applied to include all the authored contributionsexcept reference
from the Qur'in and Hadith. All the monographicand journal articles
were included, as was a random sample of conference articles.
Bibliographic information was obtained from footnotes, lists of references, notes, and bibliography. If a citation was derived from the
quotation of another document, the original citation was analyzed.
Information about chapterand verse number was recordedfor Qur'anic
referenceswhile chapter and title of the compilation were taken for
Hadith references.The citationsin APA style were notedfrom insertions
and the completebibliographic information was taken from the bibliography. Other than Qur'anic and Hadith references,only citations of
authored documents were included. In order to ascertain place of
publicationfor journals, Ulrich's Directory of Periodicalswas used. In
caseof a confusion for monographicentities or conferenceproceedings,
The National GeographicAtlas of the Worlcl was used for verification.
Nameauthority files were usedto authenticateconsistententry of author
and publishernames.A database,using INMAGIC software,was created
to record all the citation data. The "term index" featureof the database
was employedto obtain countsof occurrencesfor authors, publishers,
countries of origin, and individual sources. Altogether 3,026 citations
were analyzed for tabulating results and constructionof bibliographs
(which are the essentialinstrumentsfor testing the hypothesis).
t 1341
Isr-Rrrtrc
EcoNoMrcsLtrnn_qruRr
The first step in data analysiswas tabulatingresults.The number of
occurrencesfor each measurewas obtainedby using the sorting feature
of the citation database.A table for each of the four measureswas
constructedto tabulate data related to: frequenciesfor each measure,
number of citations, cumulative frequencyfor the measure,cumulative
citations, and the comrnon logarithm for citations (using a scientific
calculator).An exampleof suchtabulationsis given in Table I basedon
a sub-setfor the first measureof authors.The next stepwas to divide the
total number of citations into three equal zones in order to get three
zoneson the bibliograph. As the citationscould nor be distributed in
equal zones for some measures,another formula was used: authors
receivingmore than four citationsin a year, authorsreceivingmore than
one but lessthan four cirationsin a year. and rhe authorsreceivingone
or less publicationsin a year (for co-authoredpublications).Then the
ScatteringLaw of 1:n:nrwasappliedro get a multiplier. By applyingthis
formula the number of cumulativecitations and logarithm is expectedto
be proportional,which is indicatedby intersectionson a bibliographat
threepointsof the logarithmat l, 1.5, and 2.7, if the BradfordianLaw
of Scatteringis exactlyapplicable.Any departuresindicareinstabilityof
communicationpatterns and an immature state of the discipline. These
technicalitiesbecomemeaningfulwhen the resuftsare studiedtogether
with relevantbibliographsin the fullowing section.
Table 1. Author tabulation
Fr. oJ
Authors
Cum.F-r.
Citations Authors
74
5
4
3
8
2
9
2 8
2
4
22
2 0
19.5
t9
I
2
3
4
5
6
1
8
9
10
Cum.
Citations
74
r28
r66
195
z./-)
a t1
269
289
308.5
321.5
Common
Log.
0
0.301
0.477
0.602
0.699
0.778
0.845
0.903
0.954
I
Findings
The resultsof the studyare presentedaround the Iour pflmary measures
of authors,publishers,
sourcesof literature.and countriesof orisin. A
IrurplLecruer-DIscouRsE
[13s]
bibliographicexplainsthe distributionof citationsin zones.Four tables
of core authors,core publishers,core sourcesof literature,and core
countriesof origin have also beenprovided.
flxn
25(n
1n7.{8
15ff)
10m
-1
500
l'2750
o
€m
'1mi
f
0.5
7
t_,
x
am
4
IF
\
1.5
2
2.5
I
e5
Figure I. Zonesfor Atfihors
Authors
Altogether 2,460 citationswere recordedfor which personalauthorship
could be ascertained.Figure t hasbeenconstructed to apply the Law of
Scatteringon distribution of citationsby authors.
Sincethe cumulativefrequenciesand algorithm were not proportional,
intersectionsof the curve and the linear lines were used to get three
zonesof core, moderate,and diminishingproductivity. The core zone of
authorswas found at the first intersectionof the x-axis and y-axis of the
bibliograph, which is at algorithm 1.0 of the x-axis, quite consistentwith
the Bradfordian Law. It means that ten authors fell in the core by
receiving 327.5 citations(13.3% of the total). Namesof authors in this
core and the respectivefrequenciesofcitations and percentages
are given
in Table 2.
t1361
ISI,AMIC ECONOMICSLTTT,NATUNT
Table 2. Core authors
#of
%of
Contribution
Frequenc ies
Attthors
14
54
38
29
28
3.01
M. NejatullahSiddiqi
2.19
Ibn Taymiyyah
1.54
M. Umar Chapra
1.18
M o n z e rK a h f
1.14
Abul Ala al-Maududi
0.98
M. Anas Zarqa
0.89
Ibn Khaldun
0.81
M. Abdul Manan
MasudulAlam Choudhury0.79
0.77
N.H. Naqvi
.A
L+
22
20
19.5
t9
Tlre second intersectionwas found at 2.75 algoritl-rminstead of the
expected1.5, referringto the moderatelog linear zone of 686 authors
of the total. The remaining673 citations
receiving 1,460citations,5g%o
(37.7%) were for those documentswhich had been authoredby 133
authors, meaning that a large segmentof them was produced through
joint authorship. The pushingof the log linear zone to the farther end,
where the diminishing zone was expectedto occur, indicatesthat at this
point the field of Islamic economics has only two zones. lt can be
interpretedthat there is a small core which is followed by a large number
of authorswho have not establishedthemselvesin the field. It is certainly
a departurefrom the Law of Scattering.
Another major finding is that the shapeof the curve around the linear
line is different from the S shapewhich is expectedin the Bradfordian
distribution. The rising tail at the end of the curve, insteadof a "groos
drop," meant that many authors were entering the field in a zone of
arelittle citedwith virtually
diminishingproductivify.Their contributions
no impact on scholarlycontributions.This is but expectedin a budding
discipline like Islamic economics,though somewhatremoved from the
norm of stabledisciplines.
It was found that a large majority of authors (76%) in Islamic
economicshad authoredonly one document. The overall contributionof
the core authors was, however, substantial. Some corporate authors,
including international agenciesand governmentpublishers,receiveda
and authorsin Islamic
large number of citations.lt meansthat researchers
ecorromicshave to rely on these resourcesheavily. A large number of
lNter-lpcruaL DlscouRsp
[r371
citations for authorswith a single contributionor collaborationalso
explainsthis departurefrom the rule. Anotherinterestinginterpretation
of the data is thata largerpool of authorshas emergedduring the recent
pastwho are interested
in publishingin the field. If someof theseauthors
sustaintheir interestin this discipline,it would accelerate
the maturation
processof this discipline,which is still in its embryonicstageotherwise.
The sourcescitedby authorsare diversein nature;a small setof classical
rvritings are at the centre,with a very large number of contemporary
writings ranged around it ahd on the periphery. The overwhelming
amountof reltrencingto Qur'an and Hadithwas followed by references
to the classicalwritingsof Ibn TaymTyahand al-GhazalT.Thereis a need
to apply contextanalysis,anothertechniqueof bibliometrics,in order
betterto understand
the linkagesbetrveen
classicaland modernrvritinss.
Publishers
A total of 618 organizationshad publishedthe l.7ll citationsrvhose
publisherscouldbe ascertained.
Again the absenceof proportionbetween
cumulativefrequencies
and logarithmpromptedthe use of intersections
of the curve andits linearline on the bibliograph(Figure 2) derivedfrom
the publishertabulations.
2000
e71flI0
ec5
0.5
1.5
Figure 2 Zonefor Publishers
t 1381
ISLAMIC ECONOMICSLITERETUru
indicatedthe three zonesof core, moderate,and
These intersections
diminishingproductivityof publishers.[t rvasfound that six publishers
r.verein the corezonewith 335 citations(18.92%).Table 3 containsa Iist
Sixtyof core publisherswith respectivefrequenciesand percentages.
(36.02%)
were
in
the
citations
log
638
of
total
a
three publishersr.vith
(45.06%)
diminishing
in
the
zone
linear zone, leaving 798 citations
publishedby 549 publishers(88.8%).
Table 3. Core publishers
% of Citation
Frequencies
tt2
61
J
31
29
Islamic Foundation
Macmillan
Islamic Publications
Int. Centre for Research
in Islamic Economics
Ddr al Fikr
Sh. MuhammadAshraf
6.32
1.78
2.99
2.09
2.09
1.64
with
Both the coreand log linear zonesfor publisherswere inconsistent
and
at
.71
found
were
l.l7
intersections
1he
as
distribution
Bradfordian
The
respectively.
curve
x-axis,
the
on
of 1.0 and 1.5 logarithrn
ir1stead
around the linearli1e in the bibliographwas also raisingat the tail end,
indicatingthat the distribution is not hyperbolic.As this end does not
depress,it meansthat too many publishersare enteringthe field without
creating any substantial impact. The expanding fragmentation in the
ofthe absenceof a clear-cutfocus.The
publishingtrendis an expression
distancesin zone distributions from the norms were. however, not as
wide as rverefound in the caseof authordistributions.Among the six
high-yieldpublishers(Table 3), the Islamic Foundationrvasthe heaviest
cited rvith a big lead over the secondin the rank. The gaps among the
other five are marginal.
From theseresults it can be interpretedthat the publicationactivity in
lslamic economics has not reachedthe level of normal intensity.
Normally, everyacademicdisciplinehasresearchorganizations,academic
or tradepublishersthat are specializedin publishing
bodies,universities,
literature pertaining to that discipline, but in this regard, Islamic
economics lags far behind. An examination of the names of core
publishersalso reveals an inherentdeficiency. It was found that, of the
INtEr-r-scruaLDrscouRsE
il3el
six core publishers,
only one - numberfive on the list - the lnternational
Centre for Researchin [slamic Economics,could be readily identified
with the disciplineof Islamic economics,rvhile the samecould not be
said of the other five. The inclusionof Macmillan in this list indicates
that the r'vritersrely quite heavilyon the contcmporarysollrcesof modern
economics.It alsosignifiesinterdisciplinary
treatrnentby the respective
authors.
Thesefindingshaveconfirmedthat,asa discipline,Islamiceconontics
is still in its infancy. No academicinstitutionshave yet produceda
credible body of works in the field. As researchactivities in the field
become more focused at certain institutions,solne publishersmay
eventuallyspecialize
in the area.This processof maturationrvill probably
take a ferv decadesif the current interestpersists.
Specific Sources
The citations were tabLrlatedto identify rvhetherspecific sourcesof
literature of Islamic economics exhibited a pattern of diminishing
distribution.The intersections
of the curveand linear lines were usedto
identifu the core, Iinear,and diminishingzonesin the absence of the
neededproportionsbetr.veen
cumulativefrequenciesof citationsand the
common algorithm.
sm
ffio
25m
ffi
trco
15m
1ffi
s825m
o
€006
258{
0g8t
Literature
Figure 3. Zonesfor SpecificSources
for
[140]
Islelrlc Ecolrol\4ics LITSRATURE
It was found that 8 of the total 1,519sources(.527%) in the core
received582 citations(19.23%).Table 4 listscore sourcestogetherwith
the respectivefrequencies
and percentages.
The Qur'an and Hadith are,
qr:iteexpectedly,the trvo most cited sourcesreceiving 12 and 2.48o/o
of
the citations,respectively.
Table 4. Core Literature
'Utte
oJ
t_UJ
Freauencies Documents
360
15
21
27
L )
2l
l8
% of Total
Citdtions
al-Qur'an
I1.90
Hadith
2.48
Studiesin Islamic Economics
t.02
Journalof Researchin Islamic
Economics
0.89
A m e r i c a nE c o n o m i cR e v i e w s
0.89
Journalof Political Economy
0.76
Revieivof Economic Studies
0.69
Torvardsa Just MonetarySystem 0 . 5 9
The moderatezoneof productivity,log linearzone,had 375 of the 1,519
(24.69%)rvith 1,308citations(a322%); the diminishingzone
sorrrces
had 1,136citations(31.54%)in 1,136specificsources(74.79%).The
intersections
on the bibliograph'"verefound at .954 and 2.584 algorithm
on the x-axis. It meansthat the core zone is quite closeto the expected
1.0 whereasthe log linearzone, expectedat 1.5, is pushedmuch farther
insidethe domain of the dirninishingzone.This situationis quite close
to the authordistribution,meaningthat a core is available,but thereis a
fragmenteddistribution in other zonesas a large number of sourcesare
being cited, br.rtthesehave not attainedany level of substancein terms
of influenceon the discipline.The sharply rising tail of the curve is
contrary to the predictionof a "groos drop" in the Larv of Scattering.
l'his irnpliesthat the field is in its early stages.An apparentsurgeof
interest in lslamic economicscorroboratesthe finding. Leaving the
Qur'an and Hadith aside, Islamic economics,unlike other academic
disciplines,does not have a hard core. This meansthat the number of
sourcescited is large,eventhough most of them (74.8o/o)receivedonly
one citation. The absenceof a core is indicativeof a stateof fragmentation in the disciplinethat is peculiarto disciplinesin early or formative
stages.But the patternsof citing the Qur'an and Hadith supportthe
INTELLECTUALDISCOURSE
[141]
assertionthat the hard core of lslamic economicsconsistsof principles
and injunctionscontainedin the revealedsources.
indicatedthat I l7 of the
A microanalysis
of the Qur'anic references
359 citations (33%) rvere from Surat al-Baqarah. The areasof Islamic
economicswhich are relatively developedare related to transactions,
banking;and the divineprinciplesregulatingtheseare
barter,interest-free
to be fbund in this sttrah. Altogether32 verseswere cited from this
chapter;Verse275, which pertainsto the prohibitionof interest,had 13
citations.
The core sourcesof literatureincludeQur'an, Hadith, four journal
titles, and two monographs.Three of the four journals are related to
generaleconomics,leavingonly one title which could belongto the core
zone. Assuming that journals are an establishedmeans of scholarly
communicationin any field, the use of a single title related to the
discipline indicatesa weakness.A journal citation study may help in
identiffing additionaltitles, but the cumulativevolume of the literature
may not rvarrantsuchan investigationat this stage.Anotherobservation
is that the rvritersin the field rely heavily on the literatureof the general
economics,indicatingthat Islamiceconomicshasflvo bases:revealedand
classical sourcesfor referring to the lslamic base, and contemporary
sourcesfor referring to generaleconomics.
Countries of Origin
The fourth measure,country of origin, was analyzedby determiningthe
countries of publicationof the cited literature.The total number of
citations with relevantinformation is 2,414. It was found that cited
literaturehad originatedin 31 countries,threeof which (9.68%)were in
the core zone of distribution receiving 1,672 of the 2,414 (69.26%)
citations, with the following breakdown:United States,711; United
were
Kingdom, 625;andPakistan,336.Thirteenothercountries(41.93Yo)
in the moderate productivify or log linear zone with 69'7 citatiolts,
28.81'yoof the total. The remainingfifteen countries(48.39%) were in the
of the total. The datarvere
diminishingzonewith 45 citationsor 1.8'7Yo
usedto constructa bibliograph (Figure 4) which indicatesthat the zone
distribution is inconsistentwith the BradfordianLaw of Scattering.The
three zones were derived by getting intersectionson the curve and line
of linearity. The coreand log linear zoneintersectionswere found at .417
and 1.204insteadof the predictedlogarithmvaluesof 1.0and 1.5,on the
x-axis of the bibliograph. It means that a ferv countries had createda
much heavier core than the norm, which had also affected the point of
u42l
ISLAMIC EcoNOUICS LrrgRErUR:
second intersection.This rvas the only measurein the study lvl-rich
exhibiteda hyperbolicpattemasthe rising curveran into a straightcurve
and finally deviatedto its right, meaningit had tlie characteristicof a
"groosdrop," an indicatorof diminishingreturu.
3m0
ffi
I
2m0
'/
1872
1500
1m0
\
{
7
5S
oo'
0,2 0.4 0.6 0.8
0An
1
1.2 1.4 1.6
120{
Figure 1. Zonesfor Countries of Origin
These results have indicated that the publication activity is
concentratedin certaincountries.Publishingactivity in the moderatezone
in some countriesis likely to gain momentum,bringing them into the
high productivity zone. A crucial factor affectingthe place of origin of
publications is the publishing options exercisedby authors. Earlier
bibliometric studies have shown that many authors of developing
countriespreferto publishtheir works in the developedworld, sincethat
carriesgreaterprestige.Two countries,Malaysiaand Saudi Arabia, have
becomerecently activein publishingin this field and their frequencies
indicate that they may be on their rvay to joining the group of core
countries.
INTEIIT,cTUAL DISCOURSE
t1431
Conclusions
The resultsof this study have not providedunqualifiedsupportfor the
hypothesisthat the lslamic economicsliteratureexhibitsthe featuresof
The citationanalysishasbeenconclusive
BradfordianLar.vof Scattering.
in projectingcore authors,publishers,sourcesof literature,and countries
of origin. The citation distributionin threezonesof core,moderate,and
with the BradfordianLarv.
dirninishingproductivityhasbeeninconsistent
The featureof dirninisliingreturnswasobservedfor only one measureof
countriesof origin and the other three measuresrevealeddifferent
patterns.The failure in meeting the norms of bibliometric larv is
attributableto the fact that the disciplineis still in its formativestage.
The resultsof this study may be usedin developingcore collections
of Islarnic economics literature.The identificatiottof core authors,
of literature,andcountriesof origin should
sources
institr,rtions)/publishers,
and providing servicesin library and
be helpful in exploiting resources
institutions.
provesuggestiveto
studl'rvill
This
infbrmationorganizations.
dealingrvith
agencies,learnedbodies,and academicdepaftrnents
research
needto analyzepresent
Islamiceconomicsliterature.Theseorganizations
and future patternsof scholarlycomrnunicationand rvould do well to
identify,areas of collaborationin theory formation, developmentof
and disscminationof results.The study
rnodels,designof infrastructures.
was confinedto the Englishlanguageliteratureavailablein the library of
the lnternationalIslamic UniversifyMalaysia.A studyon a larger scale
and rvith a r.vider coverage would certainly provide a more accurate
analysisof the situation.The bibliometrictechniqueof contextanalysis
is considereduseful for the purposesof identifuingrvhatis known as the
influence pattern. The growth and progressof Islamic economics,a
discipline still in its infancy, needsto be periodicallymonitored and
examined.usins bibliometricmethodsof investigation.
Notes
1. Emilie C. White, "Bibliometrics:From Curiosity to Conventions."Special
Libraries 76 (Winter 1985):36.
2. B. C. Brookes, "Numerical Methods of BibliographicAnalysis," Library
Trends22 no. | (July 1973): 18
3. S. C. Bradford. "Sourcesof Informationon SpeciflcSubjects,"Collection
u44l
[sI-eItIc ECONOMICSLITERATURE
Managementl, no, 3-4 (Fall-Winter 1976-77):96.
4 . I b i d . ,9 9 .
5. AbrahamBookstein,"BibliometricDistributions,"Library Quarterly46, no.
4 ( O c t o b e r1 9 7 6 ) : 4 1 8 .
6. Leah A. Lievrauw, "ReconcilingStructureand Processin the Study of
ScholarlyCommunication,"in Scholarly Comnttnicationand Bibliometrics, ed.
ChristineL. Borgman.(London: SagePublications,1990),61.