Behavioral Approach to Repeated Games with Private Monitoring

Date: 2013-03
By: Hitoshi Matsushima (The University of Tokyo)
Tomomi Tanaka (Economic Development & Global Education, LLC)
Tomohisa Toyama (Kogakuin University)
We examine repeated prisoners’ dilemma with imperfect private monitoring and random termination where the termination probability is low. We run laboratory experiments and show subjects retaliate more severely when monitoring is more accurate. This experimental result contradicts the prediction of standard game theory. Instead of assuming full rationality and pure self-interest, we introduce naivete and social preferences, i.e., reciprocal concerns, and develop a model that is consistent with, and uniquely predicts, the observed behavior in the experiments. Our behavioral model suggests there is a trade-off between naivete and reciprocity. When people are concerned about reciprocity, they tend to make fewer random choices.

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)

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]


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.

Experimental practices in economics: A methodological challenge for psychologists?

Ralph Hertwig  and Andreas Ortmann (2001) “Experimental practices in economics: A methodological challenge for psychologists?." Behavioral and Brain Sciences, Volume 24, Issue 03, June 2001, pp 383-403. 提供的 [PDF]



This target article is concerned with the implications of the surprisingly different experimental practices in economics and in areas of psychology relevant to both economists and psychologists, such as behavioral decision making. We consider four features of experimentation in economics, namely, script enactment, repeated trials, performance-based monetary payments, and the proscription against deception, and compare them to experimental practices in psychology, primarily in the area of behavioral decision making. Whereas economists bring a precisely defined “script” to experiments for participants to enact, psychologists often do not provide such a script, leaving participants to infer what choices the situation affords. By often using repeated experimental trials, economists allow participants to learn about the task and the environment; psychologists typically do not. Economists generally pay participants on the basis of clearly defined performance criteria; psychologists usually pay a flat fee or grant a fixed amount of course credit. Economists virtually never deceive participants; psychologists, especially in some areas of inquiry, often do. We argue that experimental standards in economics are regulatory in that they allow for little variation between the experimental practices of individual researchers. The experimental standards in psychology, by contrast, are comparatively laissez-faire. We believe that the wider range of experimental practices in psychology reflects a lack of procedural regularity that may contribute to the variability of empirical findings in the research fields under consideration. We conclude with a call for more research on the consequences of methodological preferences, such as the use on monetary payments, and propose a “do-it-both-ways” rule regarding the enactment of scripts, repetition of trials, and performance-based monetary payments. We also argue, on pragmatic grounds, that the default practice should be not to deceive participants.
Key Words: behavioral decision making; cognitive illusions; deception; experimental design; experimental economics; experimental practices; financial incentives; learning; role playing.

Laboratory Evidence on Face-to-Face: Why Experimental Economics is of Interest to Regional Economists*

Björn Frank (2012) “Laboratory Evidence on Face-to-Face: Why Experimental Economics is of Interest to Regional Economists." International Regional Science Review, June 13, 2012. doi: 10.1177/0160017612449017. working paper PDF; Journal Web. **

Notes by yinung

此文提及 death of distance" (Cairncross, 2001) or “death of geography" 意思是

…the shrinking costs for transportation, especially transportation of messages’ pure in formation content.

必需有 face-to-face 溝通的原因是

… widely agreed that communication often must be face-to-face in order to be effective. But why?

1. nonverbal 和 verbal 同時發生,減少誤解(Storper and Venables, 2004; Winger, 2005, sections 4 – 6; and Hildrum, 2007, p. 469 with further references).

2. 比較有意義 (???待了解)

3. 發現想看到的,也發現原來沒想看到的隱含事務

4. buzzing (流言???)

5. face-to-face 溝通成本高,可視為建立長期關係之投資

6. 建立互信的必要條件

以上是理論,經濟實驗 (不含心理實驗)之證據為此文之回顧重點

匿名實驗結果有時不具參考性,此文同意此觀點 (至少用 email 溝通知道名字)

幾個與 face-to-face 相關因素

  1. 即時回應之效果 and 冷淨作用 Cooling effects: effect of spontaneity (decision time)  in Sec. 2
  2. trust 和合作受到 face-to-face 之影響 in Sec. 3
  3. 細節因素,如 smiling 和 eye contact  在 f2f 中之角色


..experiment on the effect of a substantive cooling off period in an experiment was invented by Oechssler, Roider and Schmitz (2008).

在 ultimatum game 中,8:2 和 5:5 的分餅被提出,看對手是否接受。24小時後,接受的決定可以被修改。餅獎金大小分別有 2,5,8 euros. Cooling off period 並未導致拒絕率大幅降低 (from 42.6% to 39.4%) ,且不顯著。但將 reward 變大 (期望值相同,用 lottery 方式),則拒絕率顯著大幅下降 fom 27.7% to 20.5%.

增加決策時間之壓力也有同樣的效果 (提高拒絕率) increased time pressure might well increase the rejection rate by Sutter, Kocher and Strauß (2003). 決策時間減少 (100秒 mm> 10 秒),拒絕率增加從 40.3 to 78.2%。 Cappelletti, Güth and Ploner (2008) 也有類似的發現 (180秒 vs 30 秒)。情感區 (affective system) 和 (deliberative system) 在大腦中並不相同。


在 UG 中,拒絕率上升,代表效率下降。出價者將會喜歡拒絕率降低 (因此可降低 offer); 反之,回應者將喜歡拒絕率上升。故,出價者將偏好 face-to-face 溝通。不過要注意的是 UG 是單向一次 negotiation, 一般的談判會有雙向回應

建立互信 & 合作

Valley, Moag and Bazerman (1998)

(註: 有時互信和合作很難區分 see


只有 seller 知道 V; Seller 會接受 if B>V; seller 得到 (B-V);

Buyer 只知 V~uniform(0,100), 真實 V 要等 Buyer 買到以後才知道。真實價值 = 1.5V; buyer 得到 (1.5V-B);

Buyer 問 seller V=?, 但 seller 可以 lie; 不過 face-to-face 之下,seller 顯著地比較不可能 lie (face-to face 只有 1 of 14, 7% lie; 電話 55% lie; 不匿名witten 33% lie). 有些 face-to-face 的 buyer 並沒有問 seller V;

結果發現 face-to-face 導致比較多的 Pareto improving deals.

Pareto deals (雙方皆獲益)

face-to-face: 51.7% (out of n=21) 成交; 顯著大於 written comm. 但不顯著大於 telephone comm.

written comm.: 22.2% (未成交 52% 接近理論值)

telephone comm.: 38.1%

Non-Pareto deals (buy’s loss):

face-to-face: 23.8%

written comm.: 25.9%

telephone comm.: 47.6%

Frohlich and Oppenheimer (1998) PD game (應是 public good game)

5人一組玩多人 PD game 共 15 回合; 前 8 回合用 (a) 事先沒有 comm.; (b) email (c) face-to-face;

每人在每回合決定貢獻 0~10 給 group, 留下其餘。

S=5人貢獻之加總; 每人皆領回 0.4S

理論:每人皆貢獻 10, 則 S = 50,每人皆領回 0.4S = 20; 若每人皆貢獻 0, 則每人只得 10


各 treatment 之平均貢獻 (前 8回合

(a) 沒有 comm: 2.9

(b) email: 7.6

(c) face-to-face: 9.99

9回合以後(皆沒有 comm.)

Contributions in groups with previous face-to-face communication quickly collapse to the level of the e-mail-groups.

face-to-face 效果持續多久

一回合就夠了? (Brosig, Ockenfels and Weimann, 2003; Bochet et al., 2006)

Rocco (1998).

6人一組玩28回合的 public good game;在第 10,15,20加入 face-to-face comm.;

每一回合貢獻 x of 13 tokens; 全部人之貢獻加總= S; 每人之 Payoffs = ???

face-to-face comm. 有助於 maximize group welfare 在後半段實驗; Email comm. 並沒有較高的合作;但實驗前一天 email comm. 的人 face-to-face 之後,卻有類似的效果。

Bochet et al. (2006)

4人10回合的 PG game;比較 5分鐘的實驗前 face-to-face vs 第 1,4,7回合 online 討論 in a chat room;


兩者差異沒有後大, 其平均貢獻:

chat room: 81.4%

face-to-face: 96.2%

但在第10回合有 drop, chat romm ->52.1%; face-to-face -> 78.1

Naquin, Kurtzberg and Belkin (2008),

玩 threshold PG game; 4 人一組;若至少有 3人 捐出 1 張餐券,則每人獲兩張 ¥7餐券 2 張;

比較 非匿名之 email 和 face-to-face 決策:

email: 35.8% of the participants 捐出

face-to-face: 69.9%


Brosig, Ockenfels and Weimann (2003)

4人一組,10回合 PG game; 其貢獻 of endowment

audio comm.: 48%

anonymous: 57%

video comm: 93%

face-to-face: 97% (後兩者顯著高於前兩者)

照片 出現 10 秒: 貢獻率低於 anonymous

Face-to-face 可能隱含的影響因素


Scharlemann et al. (2001) 在 trust game 中,發現微笑有助於合作

 Player 1 — [$1, 0.5]
Player 2 — [0.8, 1.25]
Player 1 — [1.20, 1.20]

Player 1 是受試者,Player 2 是電腦但 show 照片 (treatment 是否微笑,取自相片資料庫),只要 Player 1 選擇 trust 策略,則電腦 (Player 2) 必定也用 trust 回應。結果發現, Player 1 之回應

沒有微笑: 55.0% 選擇 trust 策略
有微笑:     68.3%

eye contact

Burnham and Hare (2007)

4人一組,6回合 PG game (對手不重覆); 其貢獻 of endowment ~ (0, 10,相當於 2 美金), 總貢獻*2 均分給 4 人.

實驗組看到金屬臉但具有人類眼睛的影像 (MIT 發明的 “Kismet” robot), 實驗結果:

匿名:        4.17

Haley and Fessler (2005)
玩 dictator game, 分$10美金, 實驗組看到眼睛圖片,對照組看到 label, 結果

Player 1 分給 Player 2

Bateson, Nettle and Roberts (2006)現地實驗中也發現,eye contact 會讓貢獻較多錢

在48位大學職員喝咖啡處貼眼睛海報 or 花海報各幾週,自願投幣奉獻 (honesty box) 金額


Frey and Bohnet (1995) 在 PD game 中讓受試者選擇合作和背叛,合作率

visual contact + talking : 78%
visual contact + no talking : 23%

Wichman (1970) 在 PD game 中讓受試者選擇合作和背叛; 70回合,固定對手,合作率

無限制的 face-to-face: 87%
互聽到聲音: 72.1%
只有 visual contact: 47.7%


The notion of face-to-face contacts has recently become very popular as a reason why firms still locate in proximity to others after the “death of distance.” Controlled laboratory experiments provide direct and reliable evidence on the importance of face-to-face contacts. It is the purpose of this article to survey and to organize new and developing string of literature with a special focus on its importance for regional economics. However, the article might also serve to alert more experimentalists to the importance of their work for current regional science, of which they seem not to be aware.

References (部份)

  • 冷卻效果
    Oechssler, Jörg, Andreas Roider and Patrick Schmitz (2008), Cooling-Off in Negotiations – Does It Work?, mimeo:
  • 決策時間長短 in Ultimatum game
    Sutter, Matthias, Martin Kocher and Sabine Strauß (2003), Bargaining under time pressure in an experimental ultimatum game, Economics Letters 81, 341–347.
  • Cappelletti, Dominique, Werner Güth and Matteo Ploner (2008), Being of two minds: an ultimatum experiment investigating affective processes, mimeo.
  • 其它
    Bateson, Melissa, Daniel Nettle and Gilbert Roberts (2006), Cues of being watched enhance cooperation in a real-world setting, Biology Letters 2, 412–414.
  • Bochet, Olivier, Talbot Page, and Louis Putterman (2006), “Communication and Punishment in Voluntary Contribution Experiments," Journal of Economic Behavior and Organization, 60, 11-26.
  • Bohnet, Iris and Bruno S. Frey (1999), The sound of silence in prisoner’s dilemma and dictator games, Journal of Economic Behavior & Organization 38, 43-57.
  • Brosig, Jeannette, Axel Ockenfels and Joachim Weimann (2003), The effect of communication media on cooperation, German Economic Review 4, 217-241.
  • Burnham, Terence C. and Brian Hare (2007), Engineering Human Cooperation. Does Involuntary Neural Activation Increase Public Goods Contributions?, Human Nature 18, 88-108.
  • Frey, Bruno S. and Iris Bohnet (1995), Institutions Affect Fairness: Experimental Investigations, Journal of Institutional and Theoretical Economics 151, 286-303.
  • Frohlich, Norman and Joe Oppenheimer (1998), Some consequences of e-mail vs. face-to-face communication in experiment, Journal of Economic Behavior & Organization 35, 389-403.
  • Haley, Kevin J. and Daniel M.T. Fessler (2005), Nobody’s watching? Subtle cues affect generosity in an anonymous economic game, Evolution and Human Behavior 26, 245–256.
  • Naquin, Charles E., Terri R. Kurtzberg and Liuba Y. Belkin (2008), E-Mail Communication and Group Cooperation in Mixed Motive Contexts, forthcoming: Social Justice Research,
  • Rocco, Elena (1998), Trust Breaks Down in Electronic Contexts but Can Be Repaired by Some Initial Face-to-Face Contact, Proceedings of the SIGCHI conference on Human factors in computing systems 1998, 496-502.
  • Scharlemann, Jörn P.W., Catherine C. Eckel, Alex Kacelnik and Rick K. Wilson (2001), The value of a smile: Game theory with a human face, Journal of Economic Psychology 22, 617-640.
  • Valley, Kathleen L., Joseph Moag and Max H. Bazerman (1998), ‘A matter of trust’: Effects of communication on the efficiency and distribution of outcomes, Journal of Economic Behavior and Organization 34, 211-238.
  • Valley, Kathleen, Leigh Thompson, Robert Gibbons and Max H. Bazerman (2002), How Communication Improves Efficiency in Bargaining Games, Games and Economic Behavior 38, 127-155.
  • Wichman, Harvey (1970), Effects of Isolation and Communication on Cooperation in a Two-Person Game, Journal of Personality and Social Psychology,16, 114-120.; DOI;


PD game
Frey and Bohnet (1995) J Inst. & Theo. Econ.
visual contact + talking : 78%
visual contact + no talking : 23%
Wichman (1970) J Per & Soc Psy
無限制的 face-to-face: 87%
互聽到聲音: 72.1%
只有 visual contact: 47.7%
Oechssler, Roider and Schmitz (2008)
Sutter, Kocher and Strauß (2003) EL
Cappelletti, Güth and Ploner (2008) mimeo

dictator game
Haley and Fessler (2005)

Trust game
Valley, Moag and Bazerman (1998) JEBO
Scharlemann et al. (2001) (smiling 在 trust game 中) JEPsy

Public good game
Frohlich and Oppenheimer (1998) JEBO
Rocco (1998) Proceedings of the SIGCHI conference
Bochet et al. (2006) JEBO
Brosig, Ockenfels and Weimann (2003) GER
Burnham and Hare (2007) (眼睛 contact) Human Nature

Bateson, Nettle and Roberts (2006) 在現地實驗(自助咖啡投幣)