Transcript Is the veil of ignorance only a concept Hannah Hörisch

Is the veil of ignorance only a concept
about risk? An experiment
Hannah Hörisch
University of Munich
ESA 2007 World Meeting
Rome, 6/30/2007
1. Motivation
•
Topic: relationship between social preferences and
maximin principle
•
Rawls (1971):
behind veil of ignorance (VoI) society would agree that
maximin principle should constitute basis of social
contract
•
Utilitarians:
voting for maximin principle is only optimal for
infinitively risk averse individuals
•
This paper:
if people have social preferences they could be in
favor of maximin principle even if they are riskneutral
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2. Experimental design
Three treatments: based on dictator game (DG), 12 units
Treatment
Efficiency Role
# of
What is
loss
uncertainty players measured?
dictator
game
impartiality
Yes
No
2
Yes
Yes
2
Social
preferences
(Impartial) social
preferences with
risk
risk
Yes
Yes
1
Risk aversion
By comparing risk and impartiality treatment we can
separate effects of risk and impartial social preferences
behind veil of ignorance.
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3. Results (1)
1. Gender differences
• Significantly different distributions in all three treatments:
Mann-Whitney test: DG tr. p=0.061, risk tr. p=0.014, imp. tr. p=0.000
 analyze data for men and women separately
• Women (men) more concerned about equality (efficiency)
• Women are slightly more risk averse
2. Comparison of DG and impartiality treatment:
VoI does make a difference
• Mann-Whitney test:
men p=0.003, women p=0.002, pooled sample p=0.000
• Where does this difference come from? Combination of
• risk aversion (risk tr.: 80% of women, 61% of men transfer positive
amounts, averages 3.7 and 2.7) and
• impartial social preferences in impartiality tr. as opposed to egoism
in DG treatment
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3. Results (2)
3. Comparison of risk and impartiality treatment:
Is VoI only a concept about risk?
• Analysis of aggregate data:
Mann-Whitney test: men p=0.773, women p=0.011, pooled p=0.203
 significant difference between risk preferences and impartial social
preferences with risk for women, but not for men
• Analysis of individual level data:
Subjects who
transfer…
Men
91 obs.
Women
40 obs.
same amount
53%
22.5%
more in imp. tr.
24%
60%
less in imp. tr.
23%
17.5%
 For women, impartial social preferences induce an increased
concern for equality
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6. Conclusions
• Experimental design achieves to separate effects of risk
and impartial social preferences behind the veil of
ignorance.
• Findings:
– VoI does make a difference
– For men, VoI is only a concept about risk
– For women, impartial social preferences are a second
motivation behind the VoI, their effect is to increase
concern for equality
 Results for women: maximin preferences can be derived
from combination of finite risk aversion and social
preferences
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