ワークショップ
2007年度 第1回 社会班ワークショップ
第4回国際経済理工学セミナー「経済理工学における実験調査の現状と課題」と共催
- 日時
- 2007年10月5日(金) 13:00-15:40
- 場所
- 東京工業大学,西9号館7階707
- 報告概要
13:00 - 13:30
Junyi Shen, Osaka School of International Public Policy, Osaka
University
"The Spite Dilemma Revisited: Comparison between Chinese and
Japanese"
Abstract: This paper studies Chinese choice behavior in the
provision of public goods via the voluntary contribution
mechanism. The laboratory experiment conducted in China is
designed as same as that in Saijo and Nakamura (1995) i.e.
either cooperating (full contribution) or free riding (no
contribution) is predicted as the unique Nash equilibrium with a
high (larger than one) or low (smaller than one) marginal return
of contribution. Comparing the results of Chinese subjects with
their Japanese counterparts, we find that choice behavior is
significantly different across these two countries with quite
similar culture and location. Japanese subjects are more likely
to act spitefully, in contrast, Chinese subjects are more likely
to perform cooperatively. In addition, concerning the deviations
from the Nash equilibriums with different marginal returns, the
statistical results indicate that Chinese subjects behave more
consistent with the theoretical prediction in the high marginal
return case, while Japanese choice behavior seems less different
from the theoretical expectation in the low marginal return
case.
13:30 -
14:00
Kazumi Shimuzu, Waseda University
"How to resolve the social dilemma?- Role of "normative
sentiments" for the altruistic behavior-"
Abstract: Recent studies on social dilemmas suggest that the
punishment of noncooperative behavior leads to higher rates of
contribution or toward full cooperation. However, the provision
of punishment creates a second-order "free-riding" problem:
group members free-ride on the costly punishment given by
others. Few attempts have so far been made to reveal the precise
contents of "punishment": who punishes whom and why?
Experiment 1: Who punishes whom and why? :
1) Some "punishers" punish not only "free-rider" but also
"cooperators";
2) Punishment against "free-rider" and that against
"cooperators" are driven by different "emotions": the former
depends on the interactions between "general trust" and
"self-fairness", whereas the later depends principally on
"emotional sympathy".
Experiment 2: Who provides "altruistic" punishment and in which
situation?
1) Group affiliation does not drive altruistic punishment in the
absence of expectation of reciprocal benefits;
2) Punishment against "free-riders" is driven by a sentiment of
fairness.
More specifically,
2-a) the higher the endorsement of fairness, more severe the
punishment
2-b) "fair-minded" participants will punish a "free rider"
independent of their group affiliation.
14:00 -
14:30
Motoki Watabe, Waseda University
"Brain Imaging Study on Trust Information Processing"
「他者の信頼性情報に関する脳イメージング研究」
Abstract: This study aims to explore how we handle information
of other's trustworthiness by brain imaging method (fMRI). More
specifically, we are interested in brain regions where activate
when we are making judgment of other's trustworthiness. In order
to address our interest, we randomly gave two different kinds of
information to each participant. One was a strong indicator of
other's trustworthiness; the other was irrelevant information to
other's trustworthiness. By comparing these two conditions, we
tried to specify the regions activating uniquely on the
information of trustworthiness. First, we needed to specify
trust information and irrelevant information. We listed fifty
eight episodes of person's behavior. We should note that all the
trust information was negative information that indicates a
person is not trustworthy. Eighteen of them were quoted from
Kosugi and Yamagishi (1994) and rests of them were originally
developed. We then ask eighty undergraduate students how each
episode useful to detect a person's trustworthiness. We picked
up the 16 most and the 16 worst useful episodes for fMRI
experiment. The farmer is "trust information." An example is
"Person A cheated at an examination." The latter is "irrelevant
information." For example, "Person A wears glasses." Second, in
fMRI study, a participant read each of the 32 picked episodes in
every two minutes. The episodes were randomly shown by a
computer. The participants were 21 undergraduate students. They
answered trust scale (Yamagishi 1998) before the experiment and
we confirmed their trust levels are around average of Japanese
population. To specify the regions of trust information
processing, we analyzed brain activation six seconds right after
the information was shown. BrainVoyager QX (ver. 1.7.9) was used
for the standard GLM analysis. The results show that the
following regions were significantly activated: Angular Gyrus,
Anterior cingulate, left frontal lobe, right frontal lobe, and
putamen. In the past research, these regions are activated when
one makes social judgments and complicated tasks. Since trust
judgment is social and complicated task, our results are
consistent with these findings. Especially, all of the activated
regions are overlapped as the study by Delgado et. al.(2005). It
should be noted that our study finds these activations only by
giving information of an anonymous person without any decision
whereas Delgado's study finds them when the subjects actually
play trust game. It means that these regions are working not
only for decisions and feedback information of partner's past
actions but also for information processing before such
decisions and feedback information.
14:30 - 14:40: Break
14:40 -
15:10
Motoki Watabe, Waseda University
"Building Trust"
「信頼構築のための社会心理学実験」
Abstract: This research experimentally examines how people can
develop trust on potential exchange partners by different types
of sanctioning systems. In this paper, I focus on the effects of
self-sanctioning (hostage-posting) behavior on trust in dyadic
exchange situation. In a two-person trust game, the first player
has fear of exploitation by the second player and the first
player is given an option to provide self-sanctioning, which
gives punishment for exploitative behavior by oneself. My
hypotheses are: 1) the first player's trust level increases when
the second player VOLUNRARILY provides self-sanctioning and 2)
it does not when the second player IMPOSEDLY provides
self-sanctioning. In order to test these hypotheses, I conducted
three experiments. The experiment 1 and 2 support these
hypotheses, but results show that the effect of trust
development by voluntary self-sanctioning is not very strong. In
the experiment 3, I conducted an experiment that four persons
are assigned as the role of the first player, they play the game
with one person as the second player, and they have opportunity
for discussion on the second player's behavior. The results show
that group discussion amplifies the effects of voluntary
self-sanctioning resulting in the first players' trust level
significantly increases. Implications and possibility of further
research are discussed.
15:10 - 15:40
Takehiko Yamato, Tokyo Institute of Technology
"Secure Implementation Experiments"
Abstract: Strategy-proofness, requiring that truth-telling is a
dominant strategy, is a standard concept used in social choice
theory. Saijo et al. (2003) argue that this concept has serious
drawbacks. In particular, many strategy-proof mechanisms have a
continuum of Nash equilibria, including equilibria other than
dominant strategy equilibria. For only a subset of
strategy-proof mechanisms do the set of Nash equilibria and the
set of dominant strategy equilibria coincide. For example, this
double coincidence occurs in the Groves mechanism when
preferences are single-peaked. We report experiments using two
strategy-proof mechanisms. One of them has a large number of
Nash equilibria, but the other has a unique Nash equilibrium. We
found clear differences in the rate of dominant strategy play
between the two.