Risk aversion and incentive effects: Comment

Harrison, G. W., Johnson, E., McInnes, M. M., & Rutström, E. E. (2005). Risk aversion and incentive effects: Comment. American Economic Review, 95(3), 897-901.   [PDF] ucsd.edu ; [PDF] ucsd.edu;[本站PDF]

==noted by yinung==

這是 Harrison et al. (2005) 對 Holt and Laury (Risk aversion and incentive effects ,2002,  AER) 這一篇的挑戰:

===重點：===

Harrison et al. (2005, AER) 對 Holt and Laury (2002, AER) 質疑有「order effects」(An order effect occurs when prior experience with one task affects behavior in a subsequent task., p.897) 並重新做實驗，比較1x10x 和只有 10x 的結果，如下圖。

(註：Hypothetical 指只有實驗中的假設報酬數字放大，並沒有實際報酬的放大)。

不過，Harrison et al. (2005) 在畫下圖的時候，不是用實際的數字，而是用 ordered probit 預測結果畫的

 

 

Risk aversion and incentive effects

Holt, Charles A., and Susan K. Laury. “Risk aversion and incentive effects." American economic review 92.5 (2002): 1644-1655. [PDF] ucsd.edu; [PDF] alaska.edu;

see also

Harrison (2005) 對上一篇的挑戰: Risk aversion and incentive effects: Comment (2005,  AER)][PDF] ucsd.edu;[本站PDF]

以及 Holt 的回應 : Risk Aversion and Incentive Effects: New Data without Order Effects (2005,  AER)

 

==Noted by yinung==

procedures:

decision task 1. 先答完10題，事後從中「隨機」選出一題來玩，並依結果付 payment。再問是否進行 decision task 2

decision task 2. 假的 20x 報酬，但和 decision task 1 相同 (high-hypothetical ONLY treatment)

decision task 3. 真的 20x 報酬，但和 decision task 1 相同 (high-hypothetical Real Only treatment)

decision task 4. 和 decision task 1 相同，用來驗證「原來在 task 1 的風險偏好是否因 wealth effects 改變」

low-payoff treatmen

high-hypothetical treatmen

• 即使是 Holt, 在 AER 發表時，仍然要引用 Kahnenman and Tversky 的辯論 (引在最下方)
• Incentive Effects? 什麼動機
  measured as the number of safe lottery choices in each treatment (p.1653)
• safe (lottery) choices 安全選項（見下圖）：
  指前4個選 Option
  

 

引文

控制 wealth effects: 要進行第2個 high-payment 實驗時，要先放棄第1個實驗得到的錢。
To control for wealth effects between the high and low real-payoff treatments, subjects were required to give up what they had earned in the first low-payoff task in order to participate in the high-payoff decision.

==Harrison et al. 對本篇的 procedures 概述==

The subjects in the HL design were given sequences of three or four tasks, as shown in Table 1. Task #1 involved choices over lotteries with a baseline level of prizes, which we will refer to as the “1X scale.” Task #2 involved hypothetical choices over prizes with a scaled-up level of prizes, either 20X, 50X, or 90X. Task #3 repeated task #2, but with choices that involved real payoffs. Task #4 was a return to the baseline task with real 1X prizes. In some sessions, subjects were not given task #2 or task #3.1。(yinung: 呵… 這比Holt 寫得還簡要清楚)

==Kahnenman and Tversky==

The implication, that low laboratory incentives may be somewhat unrealistic and therefore not useful in measuring attitudes toward “real-world" risks, is echoed by Daniel Kahneman and Amos Tversky (1979, p. 265), who suggest an alternative:

Experimental studies typically involve contrived gambles for small stakes, and a large number of repetitions of very similar problems. These features of laboratory gambling complicate the interpretation of the results and restrict their generality. By default, the method of hypothetical choices emerges as the simplest procedure by which a large number of theoretical questions can be investigated. The use of the method relies on the assumption that people often know how they would behave in actual situations of choice, and on the further assumption that the subjects have no special reason to disguise (掩飾) their true preferences. （在實驗中，受試者沒有特別理由要掩飾他們的真實偏好）

 

Risk Aversion and Incentive Effects: New Data without Order Effects

Holt, Charles A., and Susan K. Laury. “Risk aversion and incentive effects: New data without order effects." American Economic Review 95.3 (2005): 902-912.  source: PDF [本站]

這篇是 Holt 回應 Harrison et al. (2004) 對先前發表(Holt and Laury, 2002, AER)，有無 order effects 的質礙。

==主要結論是：==

payment 愈高，risk averse 愈明顯，但沒有 order effects。

==notes by yinung==

• 用這來判斷 risk averse: The average number of safe choices(查細設定?)
• 此新實驗改用 a single lotterychoice menu?
• 1st treatment(odered choices): low-pay -> high-payment (20X)
• 另外4個 (unordered) TM
  L(1x)
  L/H0
  H(20x)
  H/H0
• 用兩個無母數檢定

==Game online==

http://veconlab.econ.virginia.edu/lc/lc.php

==references==

• Harrison, G. W., Johnson, E., McInnes, M. M., & Rutström, E. E. (2005). Risk aversion and incentive effects: Comment. American Economic Review, 95(3), 897-901.
• HOLT, Charles A.; LAURY, Susan K. Risk aversion and incentive effects. American economic review, 2002, 92.5: 1644-1655.