Title: Theories of Social Preferences II
1Theories of Social Preferences II
2Theories of social preferences - Models
- Theories of inequality aversion Subjects dont
like inequality relative to relevant comparison
groups. - Fehr Schmidt, QJE 1999
- Bolton Ockenfels, AER 2000.
- Theories of reciprocity Intentions (Kindness
or Unkindness) are explicitly modeled. - Rabin, AER 1993.
- Falk Fischbacher, GEB 2006.
- Dufwenberg Kirchsteiger, GEB 2004.
3Theories of inequality aversion
- What the models (BO, FS) have in common
- Outcome based view of fairness
- Assume that fairness intentions are irrelevant
- The models differ in the way that xj influences
Ui - FS
- BO
Share of total surplus (the utility function is
maximized in this argument if share1/n
4Warm-up
- Imagine a country with three classes (upper,
middle, lower). The middle class is in
government. Whom would a govt with FS (BO)
preferences tax and to whom would they
redistribute? - Both models make identical qualitative
predictions for many games. Can you think of (or
remember) a game for which this would not be the
case?
5Falk, Fehr and Fischbacher (Ectra, 2003)- Design
- Three person one-shot public goods game with
punishment opportunity - 1st Stage public goods game
- Contribute 20 points (cooperate) or nothing
(defect) - Payoff
- 20 - own contribution
- 0.6 sum of all contributions
6Falk, Fehr and Fischbacher (Ectra, 2003)- Design
- 2nd stage Reduce the other player's payoff at a
cost - Punishing cooperators 1 point reduction costs .3
points. - Punishing defectors 1 point reduction costs .4
points. - It is cheaper to punish cooperators.
- How does this design generate different
predictions for BO and FS?
7Falk, Fehr and Fischbacher (Ectra, 2003) -
Predictions
- BO predict that if cooperators punish, they
punish other cooperators. - It is the cheapest way to reduce inequity because
it reduces the average payoff of the other
players most - How does Ui depend on p-I Share pi/Spj
- Inequity measured towards the whole group and not
individually - FS predicts that if cooperators punish, they
punish defectors. - Because fairness is evaluated for each other
player separately, those are punished who
deserve punishment because they have a higher
payoff (FS)
8Falk, Fehr and Fischbacher (Ectra, 2003) -
Experimental Results
9Theories of Inequality Aversion - Summary
- Models of inequality aversion are consistent with
the experimental results in large class of games. - They (in particular FS) have become very popular,
also because of their tractability. - However, they are likely to mispredict in certain
situations as the following example will show...
10Which hypothesis was tested with the following
experiment?
Treatment 1
Treatment 2
10/27
17/27
1/3
11/17
2/3
6/17
Intentions matter!
McCabe et al, JEBO 2003
11Theories of reciprocity - Models
- Theories of reciprocity
- Rabin, AER 1993.
- Falk Fischbacher, GEB 2006.
- Dufwenberg Kirchsteiger, GEB 2004.
-
- Reciprocity willingness to reward kind behavior
and to punish unkind behavior even at a cost to
oneself - Which behavior is kind and which unkind?
- Intentions (Kindness or Unkindness) are
explicitly modeled
12A Game Tree and Psychological Game Theory
- Is player 1s move B kind or unkind?
- Kindness depends on what player 1 expects player
2 will choose. Why? - (second order) beliefs are important
- Concept of Psychological Game Theory
Geanakoplos, Pearce, Stacchetti (1989) - Example by Dufwenberg and Kirchsteiger
1
A
B
2
1 1
C
D
0 2
2 0
13Psychological Game Theory Geanakoplos, Pearce,
Stacchetti (GEB 1989)
- Remarks
- Beliefs are not part of the action space, i.e.,
beliefs cannot be formed strategically. - Psychological Nash equilibrium Nash equilibrium
plus the requirement that all beliefs match
actual behaviour. - Reciprocity models are psychological games.
14Reciprocity models Rabin (AER 1993) Falk
Fischbacher (2006) Dufwenberg Kirchsteiger
(GEB 2004)
- Structure of reciprocity models
- Ui pi ri S Kindness j to i Response i to j
- (Response is often modelled with pj)
- If the other player is kind (kindness gt0), then
player i chooses a positive response. - If the other player is unkind (kindness lt0), then
player i chooses a negative response.
15Reciprocity Models (Rabin,DK,FF)
- Models differ by what determines kindness
- Payoff that player i is supposed to receive
compared to reference payoff - Absolute reference (FF)
- Intentions and outcomes count. Kindness is based
on interpersonal comparisons. - Relative reference (R, DK)
- reciprocity is exclusively intentions driven
- people do not consider whether they have more or
less than their opponents, rather compare
actually chosen outcome with alternative actions
opponents could have chosen - Intentions are incorporated into the theory by
considering the alternatives.
16Intentions
- DK predicts zero rejection rate when 82 is
offered - Subjects do not consider the 82 offer as unkind
because 100 is even more unkind. - FF predict positive rejection rates
- Fairness is determined by the outcome and the
intention of the other subject. - 9 of subejcts actually reject 82
17Conclusion
- Fairness can be captured by incorporating
preferences for fairness into the utility
function. - Models reconcile results with equal outcomes as
well as with unequal outcomes (e.g. UG vs.
competitive markets). - Fairness is evaluated individually.
- Intentions and outcome matter.
- Reciprocity models give a better description of
human behavior but at a cost in tractability.
18Do the Reciprocal Trust Less?Dohmen et al.
(forthcoming), Economics Letters
19Motivation
- Test a within subject prediction of several
theories of social preferences for the trust game
x 3
Sender
Receiver
Endowment 3 t - amount returned
Endowment t amount returned
20Motivation
- Test a within subject prediction of several
theories of social preferences for the trust game - These theories predict (ceteris paribus)
- Subjects who are inequality averse/reciprocal
should - return more, i.e., be more trustworthy as
receivers and - trust less, i.e., send a smaller amount t as
senders - than their selfish counterparts.
- Intuition?
21Motivation
- Selfish sender just suffers from the loss of her
investment if receiver sends back too little - Inequality averse/reciprocal sender experiences
additional disutility because payoffs are
unequal/his trust has been exploited (unkind
action). - Fehr et al. (2007) fairness preferences inhibit
trusting behavior because trust typically
involves a risk of being cheated.
22Warm-up
- What would an ideal data set to test this
prediction look like?
23We use a trust game to measure trust and
reciprocal inclination.
- Two players with an endowment of 120 each
- Amount sent t used as a measure of trust
- Amount returned used to construct a measure of
reciprocity.
x 3
Sender
Receiver
120 3 t - amount returned
120 t amount returned
24Our design measures trust and reciprocity for
each subject in the same strategic environment.
- We use the strategy method to elicit each
subjects trust and reciprocal inclination - Subjects make decisions for both roles
- For the role of the receiver subjects decide how
much to send back for any possible amount
received - Random mechanism determines actual role at the
end of experiment - Trust game played only once in anonymously
matched pairs
25We construct a reciprocity measure from the
choices made for the amount returned.
- Trust Amount Sent
- Reciprocity data on amount returned for every
potential amount sent
26We measure reciprocity in the following way.
- Reciprocity data on amount returned for every
potential amount sent - Coefficient r from OLS without constant as
measure for reciprocity
Completely selfish r 0
27We measure reciprocity in the following way.
- Reciprocity data on amount returned for every
potential amount sent - Coefficient r from OLS without constant as
measure for reciprocity
Sending back the amount received r 1
28We measure reciprocity in the following way.
- Reciprocity data on amount returned for every
potential amount sent - Coefficient r from OLS without constant as
measure for reciprocity - Selfish r 0
- Intermediate 0lt r lt 1
- Reciprocal r gt 1
Splitting the pie equally r 2
29Distribution of reciprocity coefficients
30The reciprocal trust more.
- Subjects who split equally trust most (amount
sent 83.5)
31The reciprocal trust more.
32There are (at least) two plausible
interpretations for our results.
- Norm adherence
- People may value the adherence to a certain norm
in itself - Norm dictating cooperative behavior in both roles
could explain our main finding - Systemmatic heterogeneity in beliefs
- Reciprocal and selfish types may have different
beliefs regarding the behavior of others - Example False consensus effect
- Could lead different types to select into
different institutional settings
33Conclusions
- Strong positive relationship between a persons
reciprocal inclination and her trusting behavior - Further research needed on underlying driving
force(s) of main finding