Economics of incentivization and social preferences: A lesson from classroom experiment and meta-study

Last registered on June 04, 2025

Pre-Trial

Trial Information

General Information

Title
Economics of incentivization and social preferences: A lesson from classroom experiment and meta-study
RCT ID
AEARCTR-0016088
Initial registration date
May 25, 2025

Initial registration date is when the trial was registered.

It corresponds to when the registration was submitted to the Registry to be reviewed for publication.

First published
June 04, 2025, 6:48 AM EDT

First published corresponds to when the trial was first made public on the Registry after being reviewed.

Locations

Region

Primary Investigator

Affiliation
Asian Development Bank Institute

Other Primary Investigator(s)

PI Affiliation
School of Political Science and Economics, Waseda University

Additional Trial Information

Status
On going
Start date
2025-05-01
End date
2025-12-31
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Understanding the significance of social preferences, especially other-regarding preferences, is essential for various economic and social aspects such as market performance, collective actions, public goods provision, and pro-environmental behaviors (Fehr & Fischbacher, 2002; Charness & Rabin, 2002; Leibbrandt, 2012; Bauer et al., 2016; Iwasaki, 2023). The nature of social preferences and their measurement have a long history in both psychology and economics (De Cremer & Van Lange, 2001; Fehr & Fischbacher, 2002; Murphy & Ackermann, 2014). In psychology, social preferences refer to the personality traits and behavior to consider the welfare of others, such that individuals with prosocial preferences tend to behave more prosocially than individuals with pro-self preferences (De Cremer & Van Lange, 2001; McClintock & Allison, 1989; Murphy et al., 2011; Van Lange et al., 2011). Economics literature defines a social preference as an individual’s preference regarding the payoffs of others, such as how the individual ranks possible combinations of personal payoffs and the payoffs of others (Charness and Rabin, 2002; Levitt & List, 2007). These preferences manifest in behaviors like altruism, fairness, and cooperation. The primary traditions for measuring social preferences in economics are revealed and stated preferences. Revealed preferences are inferred from actual behavior in specific tasks, such as dictator games or public goods games, whereas stated preferences are derived from self-reported data on hypothetical or real-world behaviors (Beshears et al., 2008). Behavioral economics measures social preferences via experimental tasks where individuals make decisions that affect their own payoffs and those of others. Common examples include the ultimatum and trust games, which have been widely used to study fairness and reciprocity (Kerschbamer et al., 2017). These measures help uncover the structural properties of tasks and environments that influence social behaviors. On the other hand, psychologists rely on self-report measures that involve asking individuals to rate their willingness to engage in prosocial behaviors or their attitudes toward fairness and cooperation (Van Lange et al., 2011). These measures are used to study stable individual characteristics and are included in various large-scale surveys and panel studies (Chuang & Schechter, 2015; Kuroishi & Sawada, 2024). Self-reports offer insight into enduring traits but may lack the precision of behavioral tasks in predicting real-life actions. Additionally, psychologists utilize social value orientation (SVO) measures to gauge social preferences without incentivizing it (De Cremer & Van Lange, 2001; Murphy et al., 2011; Van Lange et al., 2011; Murphy & Ackermann, 2014). In psychology, human traits are evaluated considering the temporal stability and predictive validity of social preference measures, which are crucial factors. Self-report assessments of social preferences exhibit more excellent temporal stability than behavioral measures, suggesting they more effectively capture consistent individual traits (Bohm et al., 2021; Froehlich et al., 2021). Nonetheless, the disparity between self-reported (non-incentivization) and actual decisions (incentivization) is an ongoing debate for accurately assessing social preferences.
Although incentivized experiments have a good rationale, recent evidence suggests that incentivization may not always matter, it might have a crowding out effect (Forsythe et al., 1994; Grech et al., 2022). Also, Matousek et al., (2022), conduct meta-analysis and suggest that it does not matter systematically for the reported discount rates whether experiments use real or hypothetical rewards. Thus, several open questions exist, such as why incentivization may not always matter in experimental economics. What payment conditions can be used in laboratory experiments, and how do they affect the outcome? What are the temporal stability, convergent validity, and predictive validity in experiments with or without incentives (Svorenčík & Maas, 2016; Mata et al., 2018)?
Therefore, the proposed study aims to examine the economics of incentivization and social preferences (SVO) through classroom experiments. It is crucial to understand whether incentivizing participants affects their other-regarding preferences (SVO) authenticity. Previous research suggests that incentivization may misalign motivations and lead to biased outcomes in understanding cooperative behaviors (Bowles & Hwang, 2008; Matousek et al., 2022). Therefore, this study will explore the necessity and impact of incentivization on social preferences, contributing to the broader discourse on temporal stability, convergent validity, and predictive validity in effective experimental methodologies and the evolution of economic theories (Camerer et al., 2000).
Three aspects of the study:
Temporal Stability:
Convergent Validity:
Predictive Validity:
Experimental procedure: (Blanco et al., 2011; Bowles & Hwang, 2008; Bowles & Polania-Reyes, 2012).
1. The experiments will be conducted in a classroom setting using randomization and using a within-subject design. We begin by collecting baseline measurements of the dependent variable(s) to establish a starting point for each participant. This baseline helps us assess changes caused by the intervention, i.e., incentivization. The participants first participate in a different set of economic games without incentivization.
2. Participants play a dual role in this within-subject Design, serving as both the treatment and control groups. This unique set-up significantly enhances the statistical power by minimizing error variance associated with individual differences. The Design’s key advantage lies in its ability to compare various conditions or treatments within the same group of participants, thereby facilitating a more direct comparison of the effects of incentivization on the dependent variable(s).
3. The participants will be a diverse group comprising undergraduate and graduate students from various disciplines such as business, economics, and engineering; this set-up plays a pivotal role in our research. Their enrollment in a wide range of courses ensures a diversity in sample, with individuals exhibiting a spectrum of knowledge and decision-making skills. The experiments are designed to elicit economic decision-making behavior, with participants being assigned to first conditions as non-incentivized and later playing the same incentivized game.
Expected Outcomes:
• Contribution to the existing knowledge on incentivization in economics and social preferences.
Ex-Ante Hypothesis 1 (H₁):
Social value orientations (e.g., altruism, fairness) exhibit temporal stability over short periods (e.g., weeks/months), even when incentivization is introduced.


External Link(s)

Registration Citation

Citation
Kamijo, Yoshio and Raja Timilsina. 2025. "Economics of incentivization and social preferences: A lesson from classroom experiment and meta-study ." AEA RCT Registry. June 04. https://doi.org/10.1257/rct.16088-1.0
Experimental Details

Interventions

Intervention(s)
Experimental procedure: (Blanco et al., 2011; Bowles & Hwang, 2008; Bowles & Polania-Reyes, 2012).
1. The experiments will be conducted in a classroom setting using randomization and using a within-subject design. We begin by collecting baseline measurements of the dependent variable(s) to establish a starting point for each participant. This baseline helps us assess changes caused by the intervention, i.e., incentivization. The participants first participate in a different set of economic games without incentivization.
2. Participants play a dual role in this within-subject Design, serving as both the treatment and control groups. This unique set-up significantly enhances the statistical power by minimizing error variance associated with individual differences. The Design’s key advantage lies in its ability to compare various conditions or treatments within the same group of participants, thereby facilitating a more direct comparison of the effects of incentivization on the dependent variable(s).
3. The participants will be a diverse group comprising undergraduate and graduate students from various disciplines such as business, economics, and engineering; this set-up plays a pivotal role in our research. Their enrollment in a wide range of courses ensures a diversity in sample, with individuals exhibiting a spectrum of knowledge and decision-making skills. The experiments are designed to elicit economic decision-making behavior, with participants being assigned to first conditions as non-incentivized and later playing the same incentivized game.
Intervention (Hidden)
Intervention Start Date
2025-06-01
Intervention End Date
2025-11-30

Primary Outcomes

Primary Outcomes (end points)
Social Value Orientation (SVO) Scores
Degree of consistency in individual SVO scores over time
The extent to which SVO scores predict real-world aligned behaviors such as intention to donate, volunteer, or support pro-social policies.
Changes in cooperation, defection, fairness, and altruistic giving across incentivized vs. non-incentivized conditions.
Baseline personality traits, including empathy, risk aversion, and competitiveness.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
Experimental Design:
Our research focuses on conducting three distinct behavioral experiments to explore various aspects of decision-making and social preferences.
• Prisoner dilemmas experiment: In the second experiment, we deal with cooperation and conflict resolution using the classic prisoner dilemma paradigm. Participants are tasked with strategic decision-making, deciding between cooperation and defection across repeated interactions. Our hypothesis also ventures into uncharted territory, examining the potential impact of incentives on decision-making within this context. We are eager to investigate whether there are discernible differences in behavior when incentives are present compared to when they are absent. Does incentivization truly matter in influencing participants’ choices and shaping their cooperative strategies? The comparison of outcomes between incentivized and non-incentivized conditions holds the promise of unveiling intriguing insights into the role of incentives in cooperative decision-making scenarios such as the prisoner dilemma.
• Other-regarding preferences experiment: Our third experiment explores other-regarding preferences, focusing on altruism, fairness, and social preferences beyond self-interest. Through behavioral measures, surveys, and economic games such as the Ultimatum Game or Dictator Game, our objective is to unveil patterns of prosocial behavior, perceptions of fairness, and the influence of social norms on decision-making processes. Our experiment is designed to examine the role of incentivization within these contexts. We aim to investigate whether incentives notably impact participants’ other-regarding preferences and their willingness to engage in prosocial behaviors. By comparing outcomes between incentivized and non-incentivized conditions, we aim to understand how incentives may shape social interactions, empathy, and motivations behind altruistic actions in experimental settings. These experiments, conducted with rigorous methodologies, including experimental designs, statistical analyses, and behavioral economics frameworks, yield meaningful data and draw insightful conclusions. Thus, combining insights from these three experiments, we aim to contribute to the broader understanding of human decision-making and social preferences and provide practical implications for real-world scenarios.
Experimental Design Details
Randomization Method
lottery
Randomization Unit
individual
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
200
Sample size: planned number of observations
400
Sample size (or number of clusters) by treatment arms
400
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
The study can detect a minimum difference of 2.5 percentage points in sharing between incentivized and non-incentivized conditions. It is powered to detect small-to-moderate effects (e.g., 2.5–7.4 percentage points).
IRB

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number

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Intervention

Is the intervention completed?
No
Data Collection Complete
Data Publication

Data Publication

Is public data available?
No

Program Files

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Reports & Other Materials