This paper shows experimentally that hearing expert opinions can be a double-edged sword for collective decision making. We present a majoritarian voting game of common interest where committee members receive not only private information, but also expert information that is more accurate than private information and observed by all members. In theory, there are Bayesian Nash equilibria where the committee members' voting strategy incorporates both types of information and access to expert information enhances the efficiency of the majority decision. However, in the laboratory, expert information had excessive influence on the voting behaviour and prevented efficient aggregation of individual information. We find a large efficiency loss due to the presence of expert information especially when the committee size is large. Using an incentivized questionnaire, we find that many subjects seVerely underestimate the efficiency gain from information aggregation and they follow expert information Much more frequently than efficiency requires. This suggests that those who understand the efficiency gain from information aggregation and perceive the game correctly might nonetheless be "stuck" in an inefficient outcome. (C) 2017 Elsevier B.V. All rights reserved.

This paper studies information transmission between an uninformed decision maker (receiver) and an informed agent (sender) who have asymmetric beliefs ("confidence") on the sender's ability ("competence") to observe the state of nature. We find that even when the material payoffs of the players are perfectly aligned, the sender's over- and underconfidence on his information give rise to information loss in communication, although they do not by themselves completely eliminate information transmission in equilibrium. However, an underconfident sender may prefer no communication to informative communication. We also show that when the sender is biased, overconfidence can lead to more information transmission and welfare improvement.

We analyse a labour-matching model with wage posting, where - reflecting institutional constraints - firms cannot differentiate their wage offers within certain subsets of workers. Inter alia, we find that the presence of impersonal wage offers leads to wage compression, which propagates to the wages for high productivity workers who receive personalized offers.

This note shows that when the designer of a contest wishes the winner have high ability, she is better off giving a head start to one of the contestants even if they are ex-ante identical. If the contestants are ex-ante asymmetric, the designer should give a head start to the one who is more likely to have high ability. (C) 2014 Elsevier B.V. All rights reserved.

引き続き共同研究者との頻繁なやり取りを通して、基礎モデルの特に３つのセットアップについて分析を進め、１つについて均衡および比較静学の導出を行った。残りの２つにセットアップについては、計算・証明作業を続行中である。