十一月 21 2014

An Experimental Study of Persuasion Bias and Social Influence in Networks

==Noted by yinung==

這篇和我之前的想法有點像, 不同處在於, 我是以小團體 (例如委員會) 中的資訊發表 (或擴散) 模式來探討, 並以多數決、一致決、不同意見發表能見度機率…來建構實驗; 這篇則是以連結數為主的設計 (比較適合一般網路世界)。

突然產生一個研究想法, 若 one of the committee members 想要增加他自已的影響力, 他才有過度發表 (宣傳) 他的意見的動機; 故在實驗設計中:

1. 每個 agent 有自已的 private signals (各有準確的機率), 或某些人還有 public reputation (比自己的 private signal 準確率高/低)

2. 每個 agent 動機都是為 group 好 / 加入 agent 自已的 utility, 認同他的人愈多, 則 utility 愈大)

3. 這個特別的 agent 可能是經理, 主席, 社團領袖, 只是普通的組員 (強調不同決策形成模式)

經理: 獨裁但負全責

主席: 多數決, 責任分擔

社團領袖: 共識決, , 責任分擔

普通組員: 非意見領袖

Date:	2014-10
By:	Jordi Brandts (Institutd’AnalisiEconomica(CSIC)) Ayça Ebru Giritligil (Murat Sertel Center for Advanced Economic Studies) Roberto A. Weber (Department of Economics, University of Zurich)
URL:	http://d.repec.org/n?u=RePEc:beb:wpbels:201403&r=net
	In many areas of social life individuals receive information about a particular issue of interest from multiple sources. When these sources are connected through a network then proper aggregation of this information by an individual involves taking into account the structure of this network. The inability to aggregate properly may lead to various types of distortions. In our experiment a number of agents all want to find out the value of a particular parameter unknown to all. Agents receive private signals about the parameter and agents can communicate their estimates of the parameter repeatedly through a network, the structure of which is known by all players. We present results from experiments with four different networks. We find that the information of agents who have more outgoing links in a network gets more weight in the information aggregation of the other agents than it optimally should. Our results are consistent with the model of “persuasion bias” of De Marzo et al. (2003) and at odds with an alternative heuristic according to which the most influential agents are those with more incoming links.

三月 22 2013

Confusion and Learning in the Voluntary Contributions Game

Confusion and Learning in the Voluntary Contributions Game
Date:    2013-01
By:    Spiros Bougheas (School of Economics, University of Nottingham)
Jeroen Nieboer (School of Economics, University of Nottingham)
Martin Sefton (School of Economics, University of Nottingham)
URL:    http://d.repec.org/n?u=RePEc:not:notcdx:2013-01&r=net

We investigate experimentally the effect of consultation (unincentivized advice) on choices under risk in an incentivized investment task. We compare these choices to two benchmark treatments: one with isolated individual choices, and a second with group choice after communication. Our benchmarking treatments replicate earlier findings that groups take more risk than individuals in the investment task . In our consultation treatments we find evidence of peer effects: there is significant correlation of decisions within the peer group. However, average risk taking is not significantly different from the benchmark treatment with isolated individual choices. This latter result underlines the importance of payoff-commonality for bringing about higher risk-taking in groups.

Keywords: experimental economics, choice under risk, advice, social influence, peer effects

==notes by yinung=

此篇和已發表在 Experimental Economics 題目竟然完全相同

Bayer, Ralph-C., Elke Renner, and Rupert Sausgruber. “Confusion and learning in the voluntary contributions game." Experimental Economics (2013): 1-19. [link to EE]

Abstract

We use a limited information environment to assess the role of confusion in the repeated voluntary contributions game. A comparison with play in a standard version of the game suggests, that the common claim that decision errors due to confused subjects biases estimates of cooperation upwards, is not necessarily correct. Furthermore, we find that simple learning cannot generate the kind of contribution dynamics commonly attributed to the existence of conditional cooperators. We conclude that cooperative behavior and its decay observed in public goods games is not a pure artefact of confusion and learning.

Date:	2015-05
By:	Jordi Brandts Ayça Ebru Giritligil Roberto A. Weber
URL:	http://d.repec.org/n?u=RePEc:bge:wpaper:829&r=net
	In many areas of social life, individuals receive information about a particular issue of interest from multiple sources. When these sources are connected through a network, then proper aggregation of this information by an individual involves taking into account the structure of this network. The inability to aggregate properly may lead to various types of distortions. In our experiment, four agents all want to find out the value of a particular parameter unknown to all. Agents receive private signals about the parameter and can communicate their estimates of the parameter repeatedly through a network, the structure of which is known by all players. We present results from experiments with three different networks. We find that the information of agents who have more outgoing links in a network gets more weight in the information aggregation of the other agents than under optimal updating. Our results are consistent with the model of “persuasion bias” of DeMarzo et al. (2003).
Keywords:	persuasion bias, experiments, bounded rationality
JEL:	C92 D03 D83

Date:	2014-06
By:	Attila Ambrus (Department of Economics, Duke University) Ben Greiner (School of Economics, Australian School of Business, the University of New South Wales) Parag A. Pathak (Department of Economics, MIT)
URL:	http://d.repec.org/n?u=RePEc:swe:wpaper:2014-30&r=net
	This paper experimentally investigates how individual preferences, through unrestricted deliberation, are aggregated into a group decision in two contexts: reciprocating gifts and choosing between lotteries. In both contexts, we find that median group members have a significant impact on the group decision, but the median is not the only influential group member. Non-median members closer to the median tend to have more influence than other members. By investigating the same individual’s influence in different groups, we find evidence for relative position in the group having a direct effect on influence. These results are consistent with predictions from a spatial model of dynamic bargaining determining group choices. We also find that group deliberation involves bargaining and compromise as well as persuasion: preferences tend to shift towards the choice of the individual’s previous group, especially for those with extreme individual preferences.
Keywords:	group decision-making, role of deliberation, social influence
JEL:	C72 C92 H41