On Spillover Effects of Social Image Concerns

Last registered on May 31, 2023


Trial Information

General Information

On Spillover Effects of Social Image Concerns
Initial registration date
June 08, 2022

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 15, 2022, 10:07 AM EDT

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

Last updated
May 31, 2023, 3:06 PM EDT

Last updated is the most recent time when changes to the trial's registration were published.



Primary Investigator

University of Cologne

Other Primary Investigator(s)

PI Affiliation
University of Oxford, Department of Economics
PI Affiliation
Cologne Graduate School in Management, Economics, and Social Science

Additional Trial Information

Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
A feeling of being observed can lead individuals to behave more prosocially. Based on a static comparison of decision-making in public versus in private, this finding has been shown to be very robust across various domains of ethical decision-making. Social image concerns - often claimed as the underlying reason - are regularly exploited by charities, governments and firms in practice. However, many real-life applications are characterized by repeated decision-making and there are many contexts in which it is not possible (or too costly) to always ensure observability of actions. In this project, we explore dynamics of prosocial decision-making with a focus on the role of observability by means of an online lab experiment. In particular, we investigate whether observability of initial actions in a specific prosocial domain affects subsequent private decision-making in the same domain.
External Link(s)

Registration Citation

Grabe, Leonhard, Christoph Oslislo and Rafael Suchy. 2023. "On Spillover Effects of Social Image Concerns." AEA RCT Registry. May 31. https://doi.org/10.1257/rct.9554-1.1
Experimental Details


We conduct an online lab experiment and analyze behavior in a variant of the dictator game. Participants are repeatedly confronted with a decision situation in which they divide money between themselves and a charity. Building on research on moral balancing, our analysis focuses on the effects of a variation of circumstances of initial behavior on subsequent behavior in the same domain. In this spirit, we design a setting in which we exogenously vary the observability of initial behavior in a controlled manner while we hold the circumstances of private subsequent behavior constant across treatments. This setting allows us to examine our main research questions: Does observability of behavior lead to different subsequent private behavior and what drives positive and negative spillover effects, i.e. moral consistency and moral licensing, respectively?
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
Our main variables of interest are donation decisions across four rounds of a dictator game. Key outcome variables will be within-subject differences in decisions across rounds and between-subject differences in private round 3 (between Control and Treatment).
Primary Outcomes (explanation)
In particular, we compare donation decisions in an observed and in an unobserved setting (both within-subject as well as between-subject) and donation decisions in a private round between subjects wo have been observed in past rounds and subjects who made their decisions in private in past rounds.

Secondary Outcomes

Secondary Outcomes (end points)
As secondary outcome variables, we measure several individual-specific characteristics:
- Demographics (age, gender, occupation, donation patterns)
- Intrinsic altruism
- Preferences for consistency
- Situational self-awareness and self-perception after round 1 and after round 3
- Perceived social pressure after round 1 and after round 3
- Cognitive Reflection Test
- Personal views on Moral Licensing
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experiment consists of three parts: A pre-experimental questionnaire, a behavior experiment, and a post-experimental questionnaire. The experimental design of the main part of the experiment is a variant of a repeated dictator game over T = 4 rounds. The specific design allows us to study the effects of observability of initial behavior (rounds 1 and 2) on subsequent behavior (rounds 3 and 4) in the same domain of ethical decision-making. Each round consists of a simple real-effort task (RET) followed by a donation decision. In the real-effort task, participants earn an endowment of 7 EUR which they are asked to split between themselves and a charity (World Food Programme). Between treatment and control group, we vary observability of the RET and the donation decision of rounds 1 and 2: Participants in the treatment group are observed by another person via life webcam during rounds 1 and 2 and see themselves in rounds 3 and 4. Participants in the control group see themselves over the whole course of the main part of the experiment, i.e. rounds 1 to 4.
Experimental Design Details
Randomization Method
We randomly assign participants to either the control or the treatment group. Randomization is done by the experimenter who randomly assigns two different weblinks to participants based on the random order in which participants entered a zoom call right before the start of each session (serving the purpose of an attendance and camera check).
Randomization Unit
individual level
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
no clusters, randomization on individual level
Sample size: planned number of observations
320 participants from the CLER participant pool
Sample size (or number of clusters) by treatment arms
160 participants in each of the two treatment arms
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

Analysis Plan Documents


MD5: 19b4b7d72ed40748a5128854d20693c6

SHA1: 76033cd97e0a3d1dfc92a8e0dbb7f88caf16da58

Uploaded At: June 08, 2022


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Data Publication

Data Publication

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Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials