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DISCUSSION PAPER SERIES IN ECONOMICS AND MANAGEMENT
Leadership in Intergroup Contests
Gerald Eisenkopf
Discussion Paper No. 18-12
GERMAN ECONOMIC ASSOCIATION OF BUSINESS ADMINISTRATION – GEABA
Acknowledgments:UrsFischbacherandmyformercolleaguesattheThurgauInstituteof Economics supported the planning of this project with multiple questions andsuggestions.DeboraGehringandtheresearchassistantsoftheLakelabattheUniversityof Konstanz provided excellent support by conducting the experiment. I gratefullyacknowledge financial support for this project from the DeutscheForschungsgemeinschaft(GrantEI983/3‐1).Allerrorsremainmyown.
LeadershipinIntergroupContests
GeraldEisenkopf
UniversityofVechta
Driverstr.22,
49377Vechta
E‐Mail:gerald.eisenkopf@uni‐vechta.de
April27,2018
I. Introduction.................................................................................................................................................2
II. DesignoftheIntergroupContestExperiment..............................................................................5
III. Predictions................................................................................................................................................7
IV. Results.....................................................................................................................................................10
V. Comparisonwithvoluntarycontributionmechanism(VCM)game.................................16
VI. Conclusions...........................................................................................................................................22
References...........................................................................................................................................................23
AppendixA–InstructionsforExperimentI.........................................................................................25
AppendixB–InstructionsforExperimentII........................................................................................28
1
LeadershipinIntergroupContests
Abstract:
The paper studies how leadership recommendations and leading‐by‐example shape
behaviorinintergroupcontests.Theexperimentalresultsshowthattheleaderisakey
driver of aggregate contest expenditure. Leaders increase their expenditure
substantially once they make recommendations to the followers. The specific
expenditure recommendations have a highly significant impact on the investments of
followers. The additional impact of leading by example is rather small. A second
experimentreplicatesthetreatmentsinanoncompetitivevoluntarycontributiongame.
It reveals a remarkable consistency in the leader‐follower‐relationship across the two
games despite significant differences in the impact of the treatments on leadership
behavior.
2
I. Introduction
Social scientists, and in particular economists, increasingly use experiments to study
leadership in groups (Zehnder, Herz and Bonardi, 2017). Experiments allow for a
random assignment of leadership roles (Huck and Rey‐Biel, 2006, Arbak and Villeval,
2011)andacontrolledvariationintheavailabilityofleadershipinstruments.1Thetask
fortheexperimentalleaderresemblesthechallengesof‘realworld’groupleaders.They
wanttoovercomecooperationproblemsamonggroupmembersinordertoimplement
mutuallybeneficialoutcomes.Therefore,experiments typically implementpublicgood
gamesorothervoluntarycontributionmechanismsthat imposeasocialdilemma.This
paper provides a novel approach and focuses on group leadership in intergroup
contests,i.e.asituationinwhichtwogroupswithmultiplememberscompeteforagiven
prize.
The behavioral analysis of leadership in intergroup contests does not just help
understandinghowfamouspeoplerisetoprominence,e.g.asgeneralsinawar,asteam
captains in sport tournaments or as successful managers in competitive markets.
Perhaps more importantly, intergroup contests have some specific characteristics
relative to voluntary contribution mechanisms that provide novel insights regarding
leadershipinstrumentandtherelationshipbetweenleadersandfollowers.
First, the incentive structure in intergroup contests is peculiar (see section 3 of this
paper, or, formore general theoretical considerations, Kolmar (2013)). Unlike typical
publicgoodgames, contestswithpredetermined,andstrictlypositive,prizesgenerate
an incentive to invest some resources for the benefit of the entire group. If all other
membersof the competinggroupsabstained fromanycontestexpenditure, aminimal
effortinvestmentbyonegroupmembercoulddecisivelychangetheoddsinfavorofthe
ownteam.
Second, increasingeffortsbysomegroupmembersdecrease the investment incentives
of the other group members if they have the same belief about the behavior of the
opposinggroup.Theseinvestmentsarestrategicsubstitutes.Hence,ifleaderscontribute
heavily to theirgroup’scause, theymay induce followers to lower theirowneffort. In
noncompetitivesocialdilemmas,theinvestmentsofonegroupmemberdonotaffectthe1 Note, that another strand in the literature experimentally investigates the personality traits andincentives,whichmotivate individuals to acquire or to delegate power (e.g. Fehr, Herz andWilkening,2013)
3
incentivesoftheothergroupmembers.Theinvestmentsbecomestrategiccomplements
ifthegroupmembershaveapreferenceforreciprocity,equityand/orfairnessconcerns
(Potters, Sefton and Vesterlund, 2005, 2007, Gächter, Nosenzo, Renner and Sefton,
2013). Because of the aforementioned peculiar incentive structure in intergroup
contests,suchpreferencesmustbestrongerforfollowerstoactaccordingly.
Third,groupmembersgenerate two typesofexternaleffects if theyprovideeffort for
theirgroup.Notonlydotheygenerateabenefittotheirfellowgroupmembers(asina
typicalvoluntarycontributionscheme).Theysimultaneouslyharmthemembersofthe
opposing group because the other group has a reduced chance towin the prize. This
negativeexternalityhasnomonetary incentiveeffectbut itcanfosterapreferencefor
winning (Mago, Samak and Sheremeta, 2013, Sheremeta, 2013) or parochial altruism,
i.e. when altruism towards one’s own group goes along with hostility towards the
opposing group (Abbink, Brandts, Herrmann and Orzen, 2012). In consequence,
contestants make rather large contributions to improve the odds of their own side
(Abbink, Brandts, Herrmann and Orzen, 2010, Sheremeta, 2015). Such seemingly
excessiveinvestmentsmitigatethesocialdilemmawithinthegroupand,therefore,limit
thescopeforleadership.
The paper also contributes to the understanding of the mechanisms of Leading by
Example (LbE) as an instrument of leadership. LbE implies that a group of followers
learns about the decision of their leader before they commit themselves in the social
dilemma. Several papers show that such LbE promotes cooperation in voluntary
contributiongames(e.g.Güth,Levati,SutterandVanDerHeijden,2007,Levati,Sutter
andVanderHeijden,2007,Gächteretal.,2013).Theyalsorevealthatgroupsperform
bestwhen ledbythosewhoarecooperatively inclined.DrouvelisandNosenzo(2013)
find that a shared group identity enhances this effect. Cartwright,Gillet andVanVugt
(2013) and Gächter and Renner (2014) identify how leaders shape the beliefs of
followersinthiscontext.
It is unclear whether LbE is still effective in circumstances that foster intra‐group
cooperation anyway. Therefore I study leadership instruments in a context in which
non‐binding investment recommendation allow for simple “cheap‐talk” coordination.
The literature does not provide clear insights on this issue. Pogrebna, Krantz, Schade
andKeser(2011)observethatnon‐bindingverbalstatementsofaleaderhaveasimilar
4
aggregateeffectlikeLbEwhileDannenberg(2015)reportsarelativelyloweffectofsuch
chatmessages.MeanwhileKoukoumelis,LevatiandWeisser(2012)showthatone‐way
communicationhasabeneficialimpactoncooperation.
The evidence derives from a laboratory experiment in which two groups with three
memberseachcompeteinaTullockcontest(Tullock,1980).2Inthebaselinetreatment
each groupmember canmake a private investment in order to increase her group’s
chance of winning the prize. In the second treatment, one randomly chosen group
memberineachgroup,the ‘leader’,recommendsacontributionlevelbeforetheactual
decision.The third treatment induces leadingbyexample.The leader recommendsan
investmentlevelanddecidesaboutherowncontribution.Theothergroupmembers,the
‘followers’, see both the recommendation and the actual investment decision of the
leaderwhentheydecideabout theirowncontribution. Inordertoobtainabehavioral
benchmark,Ireplicatethetreatmentsinasecondexperimentinwhicheachgroupfaces
asocialdilemmainthecontextofanoncompetitivevoluntarycontributionmechanism
(VCM).
Theresultsshowthatfollowersdonotfree‐rideontheinvestmentsoftheleaders.They
also reveal somedifferences in investment levels across the treatments.However, the
leadersarethemaindriversof thiseffect.Theytendtounderinvestbut increasetheir
expenditure substantially once theymake recommendations to the followers. Leading
by example, i.e. the visible ex‐ante investment commitment of the leader, has no
discernible additional impact on the investment level and a small positive impact on
followership.
Thesecondexperiment shows that thebehavioraldifferencesbetween the twogames
are remarkably small, starting with the observation that they induce the same
investments in the baseline treatmentswithout recommendations. The key difference
between the two games is the observation that the VCM induces leaders to increase
expenditure more strongly than in the inter‐group contest once they make
2 The Tullock contest is arguably themost widely usedmodel for the experimental study of conflicts(Abbink,2010,Dechenaux,KovenockandSheremeta,2012,Kimbrough,LaughrenandSheremeta,2017).Thegroupmemberscaninvestresourcesinordertoincreasetheprobabilitytowinaprize.Anyincreaseininvestmentsimultaneouslyreducestheprobabilityoftheopposinggrouptowintheprizeinthespecificround.
5
recommendations. This extra‐large increase in investments does not affect the
comparativestaticsoffollowership.
The paper now proceeds as follows. The next sections explain the design of the
intergroupcontest,derivethebehavioralpredictionsandpresenttheresults.SectionV
introducesthevoluntarycontributionmechanismsandcomparesthetwoexperiments.
SectionVIprovidestheconclusions.
II. DesignoftheIntergroupContestExperiment
In the experiment two groups competed against each other in a Tullock contest. The
experiment lasted for 20 rounds, each round the group faced a randomly chosen
opponent.Agroupconsistedof threeplayers,one leaderand two followers,whokept
theirrolesthroughouttheentireexperiment.3Table1summarizesthesequenceofthe
stagegameandthetreatmentdifferences.Thegamedidnotvaryacrosstheroundsina
specifictreatment.
3AppendixAprovidesanEnglish translationof theexperimental instructions (orginal inGerman).Theinstructions did not mention terms like leadership or followers and used neutral labels, referring toplayersA,BandC(theleader).Thisprocedureshouldminimizedemandeffectsthatbesetmanyappliedexperimentalstudies(SturmandAntonakis,2015).Iusedapartner‐matchingprotocolwhichimpliesthatthegroupcompositiondoesnotchangeacrossrounds.
6
Table1:TheDesignofaroundintheExperiment
Step Baseline Recommendation LeadingbyExample
(LbE)
1 Eachplayergetsanendowmentof100points
1a Leadermakesanon‐bindinginvestment
recommendation
1b Leaderdecidesabout
investment
2
Followerslearnaboutthe
recommendation
Followerslearnabout
therecommendationand
theleader’sinvestment.
Leaderandfollowersdecideaboutinvestment Followersdecideabout
investment
3
Allplayerslearnwhetherthegrouphaswontheprize.
Leaderslearnabouttheindividualinvestmentsofthefollowersandthe
aggregateinvestmentsoftheothergroup.
I now explain the game in a round in the Baseline Treatment in greater detail.
Afterwards,Idescribethedifferencesbetweenthetreatments.
BaselineTreatment
Each player received an endowment of 100 points in a round, with 120 points
exchanginginto1€.Theplayercouldkeepthepointsinaprivateaccountorinvestthem
inordertoenhancethechancesoftheowngroupintheintergroupcontest.Thegroups
competeforaprizeof300points.Irrespectiveoftheindividualinvestments,eachgroup
member receives 100points if her groupwins. Thewinning probability of a group is
determined by its members’ investments relative to aggregate investment in both
groups.At theendofaround, the followers learnabout theirownpayoff, i.e.whether
thegrouphaswontheprize.Theleadersalsoreceiveinformationabouttheindividual
investmentsofgroupmembersandtheaggregateinvestmentsoftheopposinggroup.
7
RecommendationTreatment
In the Recommendation Treatment the leader makes a non‐binding investment
recommendation toher followers.All groupmembers see this recommendationwhen
theymaketheirsubsequentinvestmentdecision.
Leading‐by‐ExampleTreatment
IntheLeading‐by‐ExampleTreatmenttheleaderalsomakesanon‐bindinginvestment
recommendation to her followers. Afterwards the leader makes her own investment
decisions.Thefollowersseetherecommendationandtheactualcontestexpenditureof
theleaderwhentheymaketheirsubsequentinvestmentdecision.
III. Predictions
In this section I present a set of competing hypotheses. The first set derives from
standard game theory assuming common knowledge that all actors are rational and
wanttomaximizetheirownpayoff.
Thestagegameisacontestbetweentwogroups,1and2.Eachgroupincludesaleader
( , with ∈ 1; 2 ) and two followers ( and ). The groups compete for a prize
0, thewinninggroupsdividestheprize inequalsharesamong its threemembers.
Each group member receives an endowment 0 and can spend 0 to
enhance thewinning probability of her group. Thewinning probability of a group in
Tullock contest is determined by the members’ investments relative to aggregate
investmentinbothgroups.
Now we study the payoff function of a risk‐neutral follower in group 1. The payoff
increasesintheendowment aswellastheproductofthewinningprobabilityandthe
shareof theprize . Itdecreases in thecontestexpenditure.The followerchooses the
expendituretomaximizetheexpectedpayoff
max3
,
with denoting the investments of leaders and followers in the
first group and for the second group. A transformation of the
resulting first order condition yields 1, and accordingly for the other
8
group, 1.Together,thetwooptimalityconditionsimplythatbothgroups
makethesameaggregateexpenditure .Theresultingsimplificationofthefirst
optimalityconditiongivesus
12
And,becauseof ,weobtaintheinvestmentofthefollower
12
Thisresultshowsthatthe investmentsof thegroupmembersarestrategicsubstitutes
1 ,which implies theaforementioned incentiveagainst leadingbyexample.
There is an optimal aggregate best response to the behavior of the opposing group.
Whatevertheleaderprovidestothisbestresponsedoesnothavetobeprovidedbythe
followers. If the leaders do not provide any investments, the followers make all the
investments.Followersshouldreducetheirinvestmentsiftheyseeahighinvestmentof
the leader.Notealso, that the leader’srecommendationsareactually irrelevant in this
context.
Wegetmultipleequilibriawithingroupsthatshareonecrucialcharacteristics,namely
theaggregateinvestmentofallgroupmembersis .With 300
points,thepredictedaggregategroupexpenditureis25points.
Hypothesis1(commonknowledgeaboutpayoffmaximizingpreferences):
a) Aggregategroupexpendituredoesnotdifferacrossthetreatments.
b) IntheBaselineandtheRecommendationsTreatments,theinvestmentsofleaders
andfollowersdonotcorrelatewitheachother.
c) IntheLeadingbyExampleTreatmenttheinvestmentsofthefollowersdecrease
withincreasinginvestmentsoftheleader.Leaderswillinvestlessthanfollowers
inthistreatment.
Thesehypothesesarenotinlinewithanintuitiveunderstandingofleadership.Leading
by example as a concept implies that leadership behavior sets a standard the others
shouldfollow.Theyalsocontradicttwowellestablishedpatternsaboutdecisionmaking
in intergroup‐contests and the leader‐follower relationship in noncompetitive
9
environments. First, we know that group members make seemingly excessive
investments in competitive environments (Abbink et al., 2010, Abbink et al., 2012,
Sheremeta,2015).Torationalizethisbehavior,Magoetal.(2013)incorporatea‘joy‐of‐
winning’ parameter in their model. Second, leadership studies in noncompetitive
environmentsgames(e.g.Güth,Levati,SutterandVanDerHeijden,2007,Levati,Sutter
and Van der Heijden, 2007, Gächter et al., 2013) and seminal theoretical papers on
conditional cooperation (e.g. Levine, 1998, Fehr and Schmidt, 1999, Falk and
Fischbacher,2006)showthatpeopleadjusttheirbehaviortotheobserveddecisionsof
othergroupmembers,inparticularafirstmovinggroupmember.
ToincorporatetheseobservationsIextendtheutilityfunctionofafolloweringroup1
with an additional parameter , . Again, I assume common knowledge that the
parameterdoesnotdifferbetweentheparticipantsinaspecificcontest
max3
,
The new parameter depends on the treatment T and increases in the (assumed)
investment of the leader (with | 0 0and , ,
, 0). It resembles the joyof‐winning‐parameter inMagoetal. (2013)as it
impliesanonmonetaryadditionalbenefitontopoftheprizeifthegroupissuccessful.
Theparameteralscontainsareciprocalelementbecauseitincreasesintheinvestment
of the leader. The assumed differences between the treatments in the comparative
staticstakeintoaccountthattheLeading‐by‐ExampleTreatment,at least,removesthe
uncertainty about the actual behavior of the leader. The transformed optimality
conditionisnow
3, 1
The aforementioned common knowledge assumption ensures homogenous aggregate
investmentsatthegrouplevelandweobtainthefollowinginvestmentofthefollower.
12,4
10
The analysis of the comparative statics reveals that the investments of the group
members are no perfect strategic substitutes anymore , 1 . The
investmentsofthefollowersincreaseintheinvestmentoftheleaderifthechangeinthe
newparameterissufficientlyhigh.
Hypothesis2:
a) Aggregate contest expenditure per group is ordered as follows across the
treatments:
, , ,
b) The correlations between the investments of leaders and followers increase
acrossthetreatmentsinthefollowingorder
0 , , ,
IV. Results
Procedure
Thedataweregathered inninesessions, three foreach treatment,witha totalof216
subjects. All sessions took place in autumn 2016 at the Lakelab at the University of
Konstanz.Subjectswerestudents fromtheUniversityofKonstanzwhowererecruited
with the software “ORSEE” (Greiner, 2015). To gain more independent observations,
eachsessionwasdivided into twodifferentmatchinggroupsof fourgroupseach.The
opposing groupwas always chosen from the samematching group. The experiments
were computerized with the software “z‐Tree” (Fischbacher, 2007). Each subject
participated in one of the treatments only. They received written instructions and
comprehension questions that had to be answered correctly before the experiment
couldstart.AnEnglishtranslationof the instructions is included inAppendixAofthis
paper.Thesessionslastedapproximately50minutesandsubjectsreceivedonaverage
about 19 Euro (about 21 US Dollars in 2016). All subjects received their payment
privatelyattheendoftheirsession.
DescriptiveStatistics
Table2showstheleaders’averageinvestmentrecommendationsandtheactualcontest
expenditureofbothleadersandfollowersinthethreetreatmentsacrossthe20rounds.
11
Thefollowingcomparisonsrelyongroupaveragesacrossrounds,usingWilcoxonrank‐
sumandsigned‐ranktests.
Table2:Investmentrecommendationsandactualcontestexpenditureofleadersand
followers(standarddeviationsinparenthesis)
Baseline Recommendations LeadingbyExample
(LbE)
Leader
recommendations‐‐‐ 54.28(14.82) 46.06(16.44)
Leaderinvestments 27.29(19.61) 41.17(17.33) 39.43(16.13)
Follower
investments33.63(13.50) 42.04(16.32) 36.31(14.88)
Npercell:24Leaders/48Followers
Themain impression is that leaders reactmore strongly to the treatment differences
than followers do. The leaders’ investments are significantly higher in the
Recommendations andLeading‐by‐Examples treatments than inBaseline (p= .03 and
.01).Leadersalsoinvestinsignificantlylessthanfollowersinthebaselinetreatment(p=
.16, according to theWilcoxon signed‐rank test)but significantlymore if they leadby
example(p=.02,accordingtotheWilcoxonsigned‐ranktest).Meanwhile,thefollower’s
investmentsincreaseiftheleaderjustmakesarecommendation(p=.053,accordingto
theWilcoxon rank‐sum test) but they are not higher in the LbE treatmentwhen they
alsoobservetheleader’sactualinvestmentdecision.
Furthermore leaders inflate recommendations if theydonothave to reveal theirown
decisions. The leaders’ recommendations are higher in the Recommendations
TreatmentthaninthenLeading‐by‐ExampleTreatment(p=.08,accordingtotherank‐
sum test). They are also significantly higher than leader efforts in that treatment
(Wilcoxonsigned‐ranktest,p<.01)whiletheyarenotintheLbETreatment.
Leaders
Now I study the treatment differences in greater detail. The first focus is on the
investmentoftheleaders.TheestimationsinthefirsttwomodelsinTable3confirmthe
significantly lower investments in the Baseline Treatment. The Recommendations
12
Treatmentservesasabenchmarkinthesemodels.Model2includesadditionalcontrol
variableswhich increase theexplainedvariancebuthavenoqualitative impacton the
treatment comparisons. They reveal a significant decline in investment over time
(Round t, see also Figure 1) and a strong persistence of behavior across rounds
(Investment t‐1). Model 3 estimates the statistical relationship between the leaders’
recommendationsandtheirowninvestmentsinLbEandRecommendationTreatments.
This relationship ishighlysignificant. Interestingly, itdoesnotdifferbetween the two
treatments even though the followers cannot identify in the Recommendations
TreatmentwhethertheLeaderstickstoherownadvice.
Table3:OLSEstimationsonTreatmentDifferencesinLeaderInvestments(with
RecommendationsTreatmentasreference)
Dep.Var:
InvestmentLeader
Model1 Model2 Model3
(w/oBaseline)
BaselineTreatment ‐13.881** (5.037) ‐6.107** (2.784)
LeadingbyExample
Treatment‐1.742 (4.554) ‐.861 (2.460) 2.030 (5.028)
Leaderrecommendation .481*** (.062)
LbE×Recommendations .021 (.128)
Roundt(1‐20) ‐0.532** (0.100) ‐.359*** (.089)
Winnert‐1 ‐.923 (1.211) ‐.268 (1.205)
Investmentt‐1 0.547*** (0.061) .390*** (.105)
Constant 41.173*** (3.249) 24.407*** (4.164) 2.483 (4.154)
R² 0.051 0.353 .525
N(obs/MatchingGroup) 1440/18 1368/18 912/12
Inparentheses:standarderrorsclusteredatthematchinggrouplevel.Eachmatchinggroupincludedfourgroupsthatwererandomlymatchedintocontestsacrosstherounds.***:p<.01;**:p<.05;*:p<.1.
13
Figure1:InvestmentsandRecommendationsofLeadersacrosstreatmentsandovertime.
Followers
In Table 2, the seemingly small differences of the followers’ investments across the
treatments suggested that leadership has a rather limited impact in the experiment.
However,ananalysisofthebehavioralrelationshipwithingroupsrevealsthatthisisnot
the case. Table 4 shows a increase in the correlation between leader and follower
investments if leaderscanmakearecommendation.Thiscorrelation increasesagain if
the leaders lead by example. Unsurprisingly, the followers focus their decision more
stronglyontheleader’sinvestmentthanherrecommendation.
0
25
50
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
average
lead
er Inve
stments (in points)
Rounds
Leaders Baseline Leaders Recommendations Tr
Leaders LbE Recommendations Rec Tr.
Recommendations LbE Treatment
14
Table4:CorrelationsbetweenRecommendationsandInvestmentsacrosstheTreatments
BaselineTreatment Leader
investments
Follower
investments
Leaderinvestments 1 .122
Followerinvestments 1
RecommendationsTreatment Leader
recommendations
Leader
investments
Follower
investments
Leaderrecommendations 1 .576 .548
Leaderinvestments 1 .437
Followerinvestments 1
LeadingbyExampleTreatment Leader
recommendations
Leader
investments
Follower
investments
Leaderrecommendations 1 .652 .606
Leaderinvestments 1 .682
Followerinvestments 1
Table 5 explores these correlations in greater detail. Its models estimate the
investments of the followers and their statistical relationshipwith the investments of
the leader across the treatments. Again, the Recommendations Treatment serves as
reference.Model1showsthatalltreatmentdifferencesareinsignificantifwecontrolfor
theinvestmentoftheleader.Model2comparesthestatisticalrelationshipbetweenthe
investmentsoftheleaderandthefollowersacrossthetreatments.Thisrelationshipisat
its lowest in the Baseline Treatment (in which it is insignificant), increases in the
RecommendationTreatments(inwhichtheleadersrecommendationsprovideacausal
link between the two investments) and has the highest coefficient in the Leading by
ExampleTreatmentwhereonecanclaimaclearcausalimpactofleadershipinvestments
onthoseofthefollowers.Model3includesadditionalcontrolvariables.Thecoefficients
regarding the statistical relationship of the investments in the different treatments
becomesmallerbutremainsignificant.
15
Table5:OLSEstimationsontheRelationshipbetweentheInvestmentsofLeadersand
Followers(withRecommendationsTreatmentasReferenceTreatment)
Dep.Var:
Investment
Follower
Model1 Model2 Model3
InvestmentLeader .548*** (.114) 0.529*** (.124) .310*** (.080)
Baseline
Treatment
‐.794 (4.646)7.112 (8.548) 8.104* (3.860)
Baseline×
InvestmentLeader
‐.299* (.161) ‐0.273*** (0.078)
Leadingby
Example
Treatment
‐4.770 (4.045) ‐18.808** (7.857) ‐7.950** (3.423)
LbE×Investment
Leader
0.355** (.152) .140* (.073)
Roundt(1‐20) ‐0.148* (.079)
Winnert‐1 ‐1.122 (1.303)
Investmentt‐1 0.591*** (.044)
Constant 19.470*** (5.648) 20.240*** (6.615) 6.610** (3.411)
R² .097 .117 0.430
N(obs/matching
group)2880/18 2880/18 2736/72
Inparentheses:standarderrorsclusteredatthematchinggrouplevel.Eachmatchinggroupincludedfourgroupsthatwererandomlymatchedintocontestsacrosstherounds.***:p<.01;**:p<.05;*:p<.1.
The aforementioned results contradict some key predictions derived from economic
theory. In particular, they show that the investments of leaders and followers are
strategic complements.We also observe some differences in investment levels across
the treatments.However, the leaders are themaindrivers of this effect. They tend to
underinvestintheBaselineTreatmentbutincreasetheirexpendituresubstantiallyonce
theymake recommendations to the followers. Leading by example, i.e. the visible ex‐
anteinvestmentcommitmentoftheleader,hasnodiscernibleimpactontheinvestment
levelandasmallpositiveimpactonfollowership.
16
V. Comparisonwithvoluntarycontributionmechanism(VCM)game
This section discusses whether the preceding results are the result of a peculiar
characteristicoftheinter‐groupcontestorwhethertheyreflectmoregeneralaspectsin
the relationship between leaders and followers. Hence, I replicate the experimental
designinthecontextofavoluntarycontributionmechanism(VCM)asithasbeenused
intheexperimentalliteratureonleadershipsofar(Güthetal.,2007,Levatietal.,2007,
Gächteretal.,2013).
DesignandProcedure
This second experiment also lasted for 20 rounds, using a partner‐matching protocol
throughout the experiment. Again, each group consists of three randomly chosen
players, one leader and two followers who kept their roles throughout the entire
experiment. Each player received an endowment of 100 points in a round, with 120
points exchanging into 1 €. The player could keep the points in a private account or
invest them inorder to enhance thewelfareof all groupmembers. More specifically,
onepoint invested impliedamarginalper‐capita return foreachgroupmemberof .5.
pointsandaggregatereturnof1.5points.Hence,itisefficienttoinvestallpointsbutan
individual who focuses just on her own payoff will not invest any point. The
Recommendation and the Leading by Example Treatments proceeded as described
above.Attheendofaround,thefollowerslearnedabouttheirownpayoff.Theleaders
also received information about the individual investments of group members. This
secondexperimentwas conductedalsoat theUniversityofKonstanz inMayand June
2016 with 120 students from the same subject pool. The smaller sample size also
reflects thatgroups constitute truly independentobservations in this experiment.The
proceduralaspectswerethesameasinthefirstexperiments.
DescriptiveStatistics
Table6summarizestheresultsofleadershipinthevoluntarycontributionmechanism.The
RecommendationsandtheLeadingbyExampleTreatmentstreatmentsseeaparticularly
strong increase in contest expenditure. The followers’ investments are higher in
RecommendationsandLbEthaninbaseline(p<.01andp=.047,respectively;seealso
Figure2),andsoaretheinvestmentsoftheleaders(bothp‐values<.01).Interestingly,
recommendationsaresignificantlyhigherthanleadereffortsinbothtreatments(p=.01
and.03,respectively).
17
Table6:Investmentrecommendationsandactualcontestexpenditureofleadersand
followersintheVCM(standarddeviationsinparenthesis)
Baseline Recommendations LeadingbyExample
(LbE)
Leader
recommendations‐‐‐ 81.66(13.89) 73.34(21.84)
Leaderinvestments 27.56(14.94) 65.47(26.59) 67.33(25.75)
Follower
investments31.41(14.00) 65.40(25.50) 57.35(30.44)
N(leader/follower) 16/32 8/16 8/16
Figure2:InvestmentsandRecommendationsofLeadersacrosstreatmentsandovertime
intheVCM
Figure3showsthatthetwoexperimentscaneasilybecomparedbecausebothBaseline
Treatmentsyieldsimilarinvestmentlevelsofleadersandfollowersinbothexperiments
0
25
50
75
100
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
average
lead
er Inve
stments (in points)
Rounds
Recommendations Rec Tr. Recommendations LbE Treatment
Leaders Baseline Leaders Recommendations Tr
Leaders LbE
18
(The rank‐sum tests yields p = .47 for the followers and p = .72 for the leaders).
Furthermore,otherbehavioralpatternspersistacrossthegames.Forexample,follower
investmentsarehigher(insignificantly) thanthoseof leaders inbaseline,donotdiffer
fromtheminRecommendations,andarelowerinLbE(Signed‐ranktestP=.01).
Figure3:InvestmentsandRecommendationsofLeadersacrosstreatmentsandovertime
intheContestandtheVCM
Leaders
The estimations documented in Table 7 show that the Leaders’ investments increase
oncetheyhavetomakerecommendationstothefollowers(Model1).Theinvestments
alsocorrelatesignificantlywiththeirownrecommendationsirrespectiveofwhetherthe
followersareinformedabouttheirleader’sinvestmentsornot.(Model2)Againonecan
observeasignificantdeclineininvestmentovertime(Roundt)andastrongpersistence
ofbehavioracrossrounds(Investmentt‐1).
0
20
40
60
80
100
BaselineContest
Baseline VCM Rec. TreatmentContest
Rec. TreatmentVCM
LbE TreatmentContest
LbE TreatmentVCM
(recommended) contest exp
enditure (in points
Leader recommendations Leader investments Follower investments
19
Table7:LeaderInvestmentsintheVCM(withRecommendationsTreatmentasReference
Point)
Dep.Var:
InvestmentLeader
Model1 Model2
BaselineTreatment ‐14.920*** (5.305)
LeadingbyExample
Treatment1.725 (5.065) 15.614 (11.777)
LeaderRecommendation .607*** (.186)
LbE×Recommendation ‐.117 (.189)
Roundt(1‐20) ‐.569*** (.134) ‐0.643*** (0.203)
Investmentt‐1 .608*** (.073) 0.442*** (.134)
Constant 30.879*** (7.616) ‐7.086 (5.560)
R² 0.576 0.627
N(obs/MatchingGroup) 608/32 304/16
Inparentheses:standarderrorsclusteredatthematchinggrouplevel.Inthefirstexperimenteachmatchinggroupincludedfourgroupsthatwererandomlymatchedintocontestsacrosstherounds.Inthesecond,eachgroupconstitutedamatchinggroupbecausetheexperimentdoesnotallowforinteractionbetweengroups.***:p<.01;**:p<.05;*:p<.1.
Table8studiesthedifferencesintheoutcomesacrossthetwoexperiments.Bothmodel
showsthattheVCMyieldssimilarcomparativestaticsregardingleadershipbehavioras
theintergroupcontests.However,Model1alsoconfirmsthatthedifferencebetweenthe
investments of leaders in the Baseline and Recommendation Treatments is much
strongerintheVCMthanintheintergroupcontest.
20
Table8:AComparisonofLeaderInvestmentsacrosstheTwoExperiments(with
RecommendationsTreatmentasReferencePoint)
Dep.Var:
InvestmentLeader
Model1 Model2
BaselineTreatment ‐5.862** (2.522)
LeadingbyExample
Treatment‐.816 (2.284) 2.107 (4.472)
LeaderRecommendation .474*** (.058)
LbE×Recommendation .018 (.120)
Vol.ContributionMech. 10.176** (4.520) ‐11.551 (8.181)
VCM×Recommendation .154 (.140)
VCM×Baseline ‐10.727** (5.002)
VCM×LbE 2.560 (5.989) 12.760 (11.819)
VCM×LbE×
InvestmentLeader ‐.123 (.211)
Roundt(1‐20) ‐.544 (.080) ‐.427*** (.085)
Investmentt‐1 .566 (.047) .403*** (.082)
Constant 23.290 (3.239) 2.878 (3.468)
R² .462
1976/50
.621
N(obs/MatchingGroup) 1216/28
Inparentheses:standarderrorsclusteredatthematchinggrouplevel.Inthefirstexperimenteachmatchinggroupincludedfourgroupsthatwererandomlymatchedintocontestsacrosstherounds.Inthesecond,eachgroupconstitutedamatchinggroupbecausetheexperimentdoesnotallowforinteractionbetweengroups.***:p<.01;**:p<.05;*:p<.1.
Followers
Table9nowstudiestherelationshipbetweentheinvestmentsofleadersandfollowers
inthissecondexperimentingreaterdetail.Likemodels2and3inTable5,itestimates
theinvestmentsofthefollowersandtheirstatisticalrelationshipwiththeinvestments
of the leaders across the treatments. The Recommendations Treatment serves as a
benchmark.Model1showsthesignificantrelationshipbetweentheinvestmentsofthe
leaderandthefollowers.ThisrelationshipissignificantlystrongerthanintheBaseline
Treatment but (insignificantly) weaker than in the Leading by Example Treatment.
Model 2 includes the aforementioned control variables which increase the explained
21
variance but have little qualitative impact on the results. Model 3 finally provides a
combinedestimationacross the twoexperiments. Its results show that thequalitative
results regarding the leader follower relationships are the same in both experiments.
Noneofthedifferencesbetweentheenvironmentsisevenapproximatelysignificant.
Table9:OLSEstimationsontheRelationshipbetweentheInvestmentsofLeadersand
FollowersintheVCM(withRecomm.TreatmentasReferencePoint)
Dep.Var:
InvestmentFollower
Model1 Model2 Model3
InvestmentLeader 0.673*** (0.146) 0.360*** (0.088) .290*** (.074)
BaselineTreatment .216 (11.887) 1.939 (7.461) 7.802** (3.567)
Baseline×
InvestmentLeader‐0.314* (0.170) ‐0.240** (0.103) ‐.267*** (.073)
LeadingbyExample
Treatment‐22.999* (11.955) ‐11.961** (8.140) ‐7.296** (3.208)
LbE×InvestmentLeader 0.203 (0.167) 0.099 (0.111) .126* (.070)
Vol.ContributionMech. 3.717 (8.861)
VCM×Investment
Leader ‐.032 (.126)
VCM×Baseline ‐6.965 (9.246)
VCM×Baseline×
InvestmentLeader .097 (.151)
VCM×LbE ‐1.876 (14.482)
VCM×LbE×
InvestmentLeader ‐.048 (.193)
Roundt(1‐20) ‐0.422*** (0.122) ‐.231*** (.065)
Investmentt‐1 0.474*** (0.055) .612*** (.038)
Constant 21.326* (11.673) 15.197* (8.186) 6.877*** (3.273)
R² 0.510 0.626 .502
N(obs/MatchingGroup) 1280/32 1216/32 3952/50
Inparentheses:standarderrorsclusteredatthematchinggrouplevel.Inthefirstexperimenteachmatchinggroupincludedfourgroupsthatwererandomlymatchedintocontestsacrosstherounds.Inthesecond,eachgroupconstitutedamatchinggroupbecausetheexperimentdoesnotallowforinteractionbetweengroups.***:p<.01;**:p<.05;*:p<.1.
22
Overall, the results show that the behavioral differences between the two games are
remarkably small. This holds in particular for the followers. The impact of leading by
example, i.e. the visible ex‐ante investment commitment of the leader, is almost
negligible in both experiments. The key difference between the two games is the
observationthattheVCMinducesleaderstoincreaseexpendituremorestronglythanin
the inter‐group contest once theymake recommendations.This additional investment
increasedoesnotaffectthecomparativestaticsoffollowership.
VI. Conclusions
This paper studied leadership in intergroup contests, comparing the results with
evidence from leadership in a noncompetitive social dilemma. Despite meaningful
differences in the incentive structure and in aggregate behavior the results identify
remark stable behavioral patterns in the leader‐follower relationship across the two
games.Inbothcontexts,theresultsshowsimilarcorrelationsbetweentheinvestments
of leadersand followers across the treatments. Intergroup contestsdonot exhibit the
negativecorrelationbetweeninvestmentsof leadersandfollowersthatstandardgame
theory suggests. Furthermore, the environments are all characterized by
overinvestments relative to standard. The most relevant difference between the two
gamesderivesfromtheobservationthatthetreatmenteffectsonaggregateinvestment
arestrongerinthevoluntarycontributionmechanismthanintheintergroupcontests.In
thelatterenvironmentleaderscoordinatethebehaviorofthefollowersbuttheydonot
risesignificantlywhichsuggestsamorelimited,butnotnegligiblescopeforleadership
inintergroupcontests.
The paper also contributes to the understanding of the mechanisms of Leading by
Example(LbE).ItwasunclearwhetherLbEisstilleffectiveincircumstanceswhennon‐
binding investment recommendations by the leader already allow for simple “cheap‐
talk”coordination.Bothexperimentsshowthatthisadditional impactofLbEis indeed
insignificantlysmall.Thefactthatleadersmaynotfollowtheirownrecommendationsif
theydonotleadbyexampledoesnotshapethebehaviorofthefollowersdecisively.
These insights suggest that the leader‐follower‐relationship is stable across decision
makingcontexts.Leaderscancoordinatefollowerstovariouslevelsofcooperationinall
23
environments. Inallcontexts,thesuccessofleadershipthereforecruciallydependson
thecourageoftheleadertogoforhighinvestmentsforthecommoncause.
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AppendixA–InstructionsforExperimentI
TheseinstructionshavebeentranslatedfromGerman.Allsubjectsinatreatmentreceived
the same instructions. Differences between the instructions across the treatments are
highlighted.Numerical examplesandOn‐Screen control questionsarenot included.The
experimentstartedonceallsubjectshadansweredallcontrolquestionscorrectly.
Welcometothiseconomicexperiment.
Yourdecisionsandthedecisionsoftheotherparticipantswillaffectyourpayoff.Hence,
it is important that you read these instructions carefully. Please contact usbefore the
26
experimentstartsifyouhaveanyquestion.
Pleasedonottalkwiththeotherparticipantsduringtheexperiment.
Otherwisewemightexcludeyoufromtheexperimentandanysubsequentpayment.
Duringtheexperimentswealwaystalkaboutpointsthatdetermineyourincome.Atthe
end of the experimentwe convert all points into Euros, using the following exchange
rate.
120points=1Euro
Yougetyourpaymentsat theendof theexperiment in cash.Nowweexplainyou the
experimentindetail.
ExperimentalSetup
At the start of the experiment you will form a group with two randomly chosen
participants.Therearethreeteammembers,A,B,andC.ParticipantChasaspecialrole
whichwedescribebelow.Youwilllearnatthestartoftheexperimentwhetheryouare
A, B, or C. During the experiment your group will meet another group of similar
composition.Ineachyouwillmeetanotherrandomlychosengroup.
The experiment has 20 rounds. The composition of your group will not change over
theserounds.Ineachround,yourgrouportheothergroupcangetaprizeof300points.
The probability of success of your groupdepends on the inputs of itsmembers. Each
groupmembergets100points irrespectiveof thepersonal input if thegroupgets the
prize.
Atthestartofeachroundeachparticipantgets100points.Anyparticipantcanusethese
points as inputs (from 0 to 100). All points not invested will be added to the
participant’sprivateaccount.
Once the participants have decided about their inputs, these investments will be
summed up. The success probability of your group depends on the ratio of its
investmentsrelativetotheinvestmentsoftheothergroup.
Thecomputeraddsuptheinputswithinateam.Thesuccessprobabilityisderivedfrom
the ratiobetweenyour team’s inputand the sumofboth teams’ inputs. Ifboth teams
27
investthesameamountthesuccessprobabilityis50%foreachteam.Thisalsoholdsif
both teams invest 0 points. If one team makes a higher investment the success
probability isalsohigher.However, it isnotguaranteed that the teamwith thehigher
investmentalsowinstheprize.Morespecificallytheformulaforthesuccessprobability
isasfollows:
SuccessprobabilityInputofyourteam
Inputofyourteam Inputoftheotherteam
Theincomeofanygroupmemberisdeterminedasfollows:
Payofffromtheprivateaccount(=100‐Investment)
+100points(ifthegroupwinstheprize.)
=totalpayoff
ParticipantC
ParticipantChasaspecialroleintheTeam.
BaselineTreatment Recommendation
Treatment
Learning‐by‐ExampleTreatment
‐‐‐
Participant C can suggest the other group members how
many points to use as input. Both A and B get the same
recommendation. A and B can never exchange information
amongthemselves.
‐‐‐ ‐‐‐
PlayerCthendecidesabouther
own input.ParticipantsAandB
learn about this input before
theymaketheirowninvestment
decision.
At the end of a round each participant receives information aboutwhether the own
grouphasreceivedthe300points.OnlyparticipantClearnsabouttheactualinputsofA
andBandtheaggregateinputsoftheothergroup.
- NumericalExamples‐
28
Timeline
Oneroundproceedsasfollows
1. Youget100points.
2. RecommendationsandLbETreatments:InputrecommendationbyparticipantC.
3. LbETreatmentonly: InputdecisionofparticipantC.The investedpointswillbe
withdrawnfromthe100point(onlyin)
4. Inputdecisions
Baseline andRecommendationTreatments: All participants decide about
theirinputs.Theinvestedpointswillbewithdrawnfromthe100point
LbETreatment:TheparticipantsAandBlearnabouttheinputofC.They
decideabouttheirinputs.Theinvestedpointswillbewithdrawnfromthe
100point
5. DistributionofthePrize.ParticipantClearnsabouttheactualinputsofAandB
andtheaggregateinputsoftheothergroup.
Theexperimenthas20roundsthatallproceedasmentionedabove.Youwillremainin
the same group throughout the entire experiment.Wewill add up all earned points,
exchangethemintoEuroandpaythemtoyouattheendoftheexperimentincash.
AppendixB–InstructionsforExperimentII
TheseinstructionshavebeentranslatedfromGerman.Allsubjectsinatreatmentreceived
the same instructions. Differences between the instructions across the treatments are
highlighted.Numerical examplesandOn‐Screen control questionsarenot included.The
experimentstartedonceallsubjectshadansweredallcontrolquestionscorrectly.
Welcometothiseconomicexperiment.
Yourdecisionsandthedecisionsoftheotherparticipantswillaffectyourpayoff.Hence,
it is important that you read these instructions carefully. Please contact usbefore the
experimentstartsifyouhaveanyquestion.
Pleasedonottalkwiththeotherparticipantsduringtheexperiment.
29
Otherwisewemightexcludeyoufromtheexperimentandanysubsequentpayment.
Duringtheexperimentswealwaystalkaboutpointsthatdetermineyourincome.Atthe
end of the experimentwe convert all points into Euros, using the following exchange
rate.
120points=1Euro
Yougetyourpaymentsat theendof theexperiment in cash.Nowweexplainyou the
experimentindetail.
ExperimentalSetup
At the start of the experiment you will form a group with two randomly chosen
participants.Therearethreeteammembers,A,B,andC.ParticipantChasaspecialrole
whichwedescribebelow.Youwilllearnatthestartoftheexperimentwhetheryouare
A,B,orC.Theexperimenthas20rounds.
Atthestartofeachroundeachparticipantgets100points.Anyparticipantcanusethese
points as inputs (from 0 to 100). All points not invested will be added to the
participant’sprivateaccount.
Once the participants have decided about their inputs, these investments will be
summedup.Thelabmanagerincreasesthissumby50%anddistributesallthesepoints
equallyamongthegroupmembers.
Allgroupmembersbenefit inthesamewayfromyour investmentasyoubenefit from
theinputsoftheothergroupmembers.Theincomeofanygroupmemberisdetermined
asfollows:
Payofffromtheprivateaccount(=100‐Investment)
+payofffromtheinputs(=0,5sumofallinputs)
=totalpayoff
ParticipantC
30
ParticipantChasaspecialroleintheTeam.
BaselineTreatment Recommendation
Treatment
Learning‐by‐ExampleTreatment
‐‐‐
Participant C can suggest the other group members how
many points to use as input. Both A and B get the same
recommendation. A and B can never exchange information
amongthemselves.
‐‐‐ ‐‐‐
PlayerCthendecidesabouther
own input.ParticipantsAandB
learn about this input before
theymaketheirowninvestment
decision.
Attheendofaroundeachparticipantreceivesinformationabouttheownpayoff.Only
participantClearnsabouttheactualinputsofAandB.
- NumericalExamples‐
Timeline
Oneroundproceedsasfollows
1. Youget100points.
2. RecommendationsandLbETreatments:InputrecommendationbyparticipantC.
3. LbETreatmentonly: InputdecisionofparticipantC.The investedpointswillbe
withdrawnfromthe100point(onlyin)
4. Inputdecisions
a. Baseline andRecommendationTreatments: All participants decide about
theirinputs.Theinvestedpointswillbewithdrawnfromthe100point
b. LbETreatment:TheparticipantsAandBlearnabouttheinputofC.They
decideabouttheirinputs.Theinvestedpointswillbewithdrawnfromthe
100point
5. Distribution of the payments. Participant C learns about the actual inputs of A
andB.
31
Theexperimenthas20roundsthatallproceedasmentionedabove.Youwillremainin
the same group throughout the entire experiment.Wewill add up all earned points,
exchangethemintoEuroandpaythemtoyouattheendoftheexperimentincash.