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In previous work, we proposed a method to address mathematical inconvenience by extending the constant elasticity of substitution (CES) utility function in Inukai, Shimodaira, and Shiozawa (2022, ISER DP No.1195). However, the relationships between the extended CES parameters and the external measurements are yet unrevealed. To explore these empirical properties of the extended CES utility function, in this paper we construct an online experiment of Amazon Mechanical Turk workers using a modified dictator game, a public goods game, and a questionnaire. We then compare the parameters of the utility function according to the modified dictator game to behavior in the public goods game and the responses to the questionnaire. This provides evidence that the distribution parameter of the extended CES utility function measures the preference for equality or selfishness. However, we do not find any positive evidence that the substitution parameter measures the preference for efficiency.

The constant elasticity of substitution (CES) function is widely used to model distributional preferences in modified dictator games. However, it has been pointed out that its parameter interpretations are inconsistent and problematic in applications. We constructed a model to address this issue by combining two formulations of the CES function. We demonstrated that the proposed model provides consistent interpretations of parameters. Our results clarified that the conventional interpretations of the standard CES function parameters for describing distributional preferences are inappropriate. Notably, “the equality–efficiency trade-off,” a conventional interpretation of the substitution parameter, is unrelated to observed individual behaviors.

The convex time budget (CTB) method is a widely used experimental method for eliciting an individual’s time preference. Researchers adopting the CTB experiment usually assume quasi-hyperbolic discounting utility as a behavioural model and estimate the parameters of the utility function. However, few studies using the CTB method have examined parameter recovery. We conduct simulations and find that the estimation error of the present bias parameter is so large that its effect is difficult to detect. The large error is due to the improper combination of the experimental method and the utility model, and it is not a problem we can deal with after the data collection. This paper suggests the importance of running parameter recovery simulations to audit estimation errors in the experimental design.

We address a concern about the external validity, in particular, the representativeness of the sampled population, of an experiment conducted with university students. We do so by conducting large?scale (partly) incentivized online surveys of students at a Japanese university and of a sample of Japanese adults to measure individual characteristics such as cognitive ability, mentalizing skills, preferences for risk and distribution, and personality traits. While significant dif?ferences between these two samples are observed in many of these characteristics, the correlational structures among these characteris?tics are very similar in the two samples., 近年の実験経済学研究では，認知能力やリスク選好・社会的選好などの個人属性を測定し，属性変数間の関係や，個人属性と実験ゲームにおける行動の間の関係を明らかにする研究が増えている．たとえば，認知能力が高い人ほど進んでリスクを取る傾向があること (Dohmen, et al., 2010, AER) や，繰り返し囚人のジレンマゲームにおいて，認知能力が高い参加者同士のグループで協力均衡がより早期に実現すること (Proto, et al., 2019, JPE) が報告されている．個人属性の測定は，実験室実験から得られる知見について，外的妥当性，とりわけをサンプルの代表性を検証する上でも重要である．実験経済学における実験室実験はしばしば，実施の容易さのために，大学生のサンプルを使って行われる．しかしながら，大学生サンプルから得られた実験結果を，より一般的な集団に適用することが可能かどうかは自明ではない．この懸念に対処するために，Snowberg and Yariv (2021, AER) はカリフォルニア工科大学の学生サンプルとアメリカにおける一般人サンプルの両方で同一の実験課題を実施して比較検討を行い，属性変数間の相関関係の構造が 2 つのサンプルの間で類似していることを明らかにした．この結果は，学生サンプルを用いた実験研究の外的妥当性を支持する証拠の一つである．本研究では，大阪大学社会経済研究所が管理する実験参加者プールに登録されている大阪大学の学生と日本国内の一般人サンプル（オンライン調査会社 GMO リサーチのアンケート回答者パネルの登録者）を対象に，オンラインアンケート形式による個人属性測定実験を実施し，2 つのサンプルを比較した．個人属性変数として，認知能力，心の理論の能力，リスク・時間・社会的選好，および性格特性を測定した．認知能力の尺度において一般人サンプルよりも大阪大学学生サンプルの認知能力が高いなど，多くの個人属性変数において学生サンプルと一般人サンプルの間で統計的に有意な差が確認されたものの，Snowberg and Yariv (2021, AER) の結果と同様，個人属性変数の間の相関関係の構造は 2 つのサンプルで類似していることが分かった．この結果から直ちに，大阪大学の学生を対象にしてこれまで行われてた実験研究の結果の外的妥当性が保証されると結論づけられるわけではないものの，変数間の相関関係に関しては大阪大学学生サンプルから得られた結果の外的妥当性について大きな懸念はないことが明らかとなった．

We summarize the experimentally measured characteristics of the regis-tered participants of the experiments conducted at the Institute of Social and Economic Research, Osaka University. Measured characteristics include uid intelligence, risk preference (risk aversion, prudence, and temperance), social value orientation, theory of mind, personality (Big Five and Grit), ability to backward induct, as well as their general trust. We discuss reliability of these measures and correlation among them.

We study the properties of social preference parameters estimated by fitting behavioral data in the generalized dictator game to a modified CES utility function.

We study the properties of social preference parameters estimated by fitting behavioral data in the generalized dictator game to a modified CES utility function. [Retrived from osf.io/pn6ke]

自己利益を得るために嘘をつくことは、様々な場面で見られる。嘘行動が直観的なシステム１の意思決定なのか、熟慮的なシステム２の意思決定なのかを明らかにするため、実験室実験を用いて、時間制限下の嘘行動の程度が異なるか否かを検証した。被験者が嘘をついているか否かが実験者にわからないタスクを用い、実験において嘘が可能か気づいていた被験者のみを用いて分析を行った。その結果、時間制限下と時間無制限下では嘘の程度の差がないことがわかった。結果の解釈が２つ考えられる。１つは、嘘の意思決定には直観的なシステム１と熟慮的なシステム２という意思決定システムがあてはまらない、つまりよく考えようが急いで意思決定しようが嘘はつく程度は変わらない、ということである。もう１つ考えられるのは、実験デザインにおける時間制限が長すぎたということである。選択肢が表示されてから被験者がキーボードの数字を押す時間はとても短く、時間無制限下においても、平均はおよそ1.3 秒である。従って、時間制限が５秒であったとしても十分な負荷を被験者に与えられなかった可能性がある。つまり直観的なシステム１の意思決定が行われなかったとも考えられる。今後の課題として、さらに時間制限を短くした実験を行い、実験結果が変化するかを調査したい。

This paper tests the effect of risk preferences on search activities by using a laboratory experiment. We used an infinite-horizon sequential search model with no recall in which an individual gains over search. We elicit the risk preferences from observed search activities of participants and from the multiple price list (MPL) method. We found the statistically significant effect of risk preferences elicited from the MPL method on the duration of search. The search duration is on average shorter for a risk averse individual than for risk loving one, which is consistent with the theoretical prediction. The significant effect of risk preferences on search activities has not been observed in the previous literature that used search model with recall in which an individual pays from the initial endowment over search (Schunk 2009, Schunk and Winter 2009). Therefore, the correlation between risk preferences and search activities depends on the type of search models.

Our paper conducts laboratory experiments with the sequential search model to test whether participants engage in search activities in line with theoretical predictions derived from the expected utility model or the reference-dependent model, without assuming any specific formulation rule for a reference point. Our experimental results showed that the participants' search behavior did not align with the reference-dependent model. In addition, the correlation between individual preferences and search behavior reinforced our experimental results; that is, loss aversions were not significantly correlated with search behavior.

The paper develops a committee search model with ex-ante heterogeneous agents and designs laboratory experiments to test theoretical predictions. In the theoretical part of the study, there exists one and only one pivotal voter, who can perfectly and dominantly control the voting results of the committee search activities. The most important prediction is that nonpivotal voters become less picky in committee search than in single-agent search, but that a pivotal voter's voting behavior remains unchanged, regardless of the type of voting rules for the search. However, our experimental results did not support this prediction; not only the nonpivotal voters but also the pivotal voter became less picky in the committee search games. In addition, we found gender differences in voting behavior; females show more concern for other group members' payoff as well as themselves than do males.

Can we empathize effectively with someone who has a different sensitivity to physical events from ours? Or, are we susceptible to an egocentric bias in over-projection, which may lead us to under- or over-react in such cases? In this study, participants with normal visual and auditory capacity observed a video clip in which a sighted or blind target was exposed to a strong flash or high-frequency sound, while their physiological arousals during the observation were recorded. On average, participants displayed a differential arousal pattern to the aversive stimuli, according to the target's ability to perceive them. Degrees of arousal control were also correlated with dispositional differences in empathy. Participants who scored higher on the Empathic Concern subscale of Davis's IRI were better at controlling arousals in accordance with the target x Stimulus interaction. Our findings have important implications for helping disabled people while respecting their inherent dignity and individual autonomy.