Should the winner be always the same? Group bonuses to enhance competition and rotation of prizes

Last registered on February 10, 2026
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Pre-Trial

Trial Information

General Information

Title
Should the winner be always the same? Group bonuses to enhance competition and rotation of prizes
RCT ID
AEARCTR-0016921
Initial registration date
February 09, 2026

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
February 10, 2026, 6:47 AM EST

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

Locations

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Primary Investigator

Name
Lara Ezquerra
Affiliation
University of the Balearic Islands
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Other Primary Investigator(s)

PI Name
Jose M. Ortiz
PI Affiliation
Zayed University
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PI Name
Natalia Jimenez Universidad Pablo de Olavide
PI Affiliation
Universidad Pablo de Olavide
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Additional Trial Information

Status
In development
Start date
2026-02-15
End date
2027-03-01
Keywords
Behavior, Lab, Labor
Additional Keywords
JEL code(s)
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
This experiment investigates how different reward structures influence outcomes in competitive environments where the winner is always the same person. These type of incentives may be appropriate in groups where rankings are stable or where the abilities or the starting point of subjects are more important than effort.

Workers have different productivity rates. These rates are fixed throughout the experiment, which consists of 15 periods. In all periods we have the same groups of 3 participants with one having a high productivity rate and the other two sharing the low productivity rate. With this we ensure that the most productive worker is always the one with high productivity.

The experiment applies four treatments that manipulate how prizes are awarded in the competition. In Treatment 1, a “winner-takes-all” system is applied, with rankings determining a single winner each round. Treatment 2 uses the same rule, but with the restriction that the same participant cannot win consecutively, forcing changes in ranking outcomes. Treatment 3 introduces multiple prizes of unequal size, not directly proportional to performance, but maintains the possibility of repeated winners. Treatment 4 combines unequal multiple prizes with the restriction that winners must change between rounds.

Together, these treatments allow comparison between highly concentrated rewards (winner-takes-all) and more distributed but uneven incentives (multiple unequal prizes), while also testing the effects of enforced rotation in winning. This approach sheds light on how prize structures affect effort, strategy, and outcomes in creative or competitive labor markets.
External Link(s)

Registration Citation

Citation
Ezquerra, Lara, Jose M. Ortiz and Natalia Jimenez Universidad Pablo de Olavide. 2026. "Should the winner be always the same? Group bonuses to enhance competition and rotation of prizes." AEA RCT Registry. February 10. https://doi.org/10.1257/rct.16921-1.0
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Experimental Details

Interventions

Intervention(s)
The intervention consists of four distinct incentive treatments that vary the way rewards are distributed among participants competing in a repeated production task. The underlying task and group composition remain constant across treatments; only the reward structure changes.

In all conditions, participants are assigned to fixed groups of three—one high-productivity worker and two low-productivity workers—and perform the same individual task during 15 periods. Their individual scores are used to rank them within their group each round. Based on this ranking, monetary prizes are distributed according to the treatment in place.

The intervention manipulates two dimensions of the incentive environment:

Prize concentration – whether all rewards go to a single winner or are distributed among multiple participants.

Winner rotation – whether the same participant is allowed to win consecutively or whether winners must change between rounds.

Specifically:

T1: Winner-takes-all, same ranking (single winner, no rotation).

T2: Winner-takes-all, change ranking (single winner, but the same person cannot win twice in a row).

T3: Multiple unequal prizes, same ranking (rewards for multiple ranks, not proportional to performance).

T4: Multiple unequal prizes, change ranking (unequal rewards and enforced winner rotation).

By systematically varying these two dimensions, the intervention isolates the effects of reward concentration and forced turnover on effort, motivation, and adaptation in competitive settings where productivity differences are fixed and known to exist.
Intervention Start Date
2026-02-15
Intervention End Date
2027-03-01

Primary Outcomes

Primary Outcomes (end points)
Performance, effort levels, behavioral responses.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experiment will be conducted in a controlled laboratory setting using computerized individual decision tasks. Participants will be randomly assigned to fixed groups of three that remain constant throughout all 15 periods. Within each group, one participant will be assigned a high-productivity role, while the other two will be low-productivity workers. Productivity rates will be exogenously determined and remain constant across all periods to ensure that performance differences reflect the underlying productivity parameters rather than random variation or effort shocks. Participants will be informed of their own productivity level but not of the productivity levels of the other group members, although they will know that heterogeneity exists within their group.

Each period consists of a production task where participants perform a simple, measurable activity (count the number of 0 in a grid of numbers) that determines their score for that round. As an alternative instead of being productive they can select a leisure activity (e.g. read jokes or see reels) that does not contribute to production in any case. Based on individual performance, participants are ranked within their group and prizes are distributed according to the treatment condition.

The four treatments manipulate the structure and rotation of rewards:

T1: Winner-takes-all, same ranking (the top performer always receives the entire prize).

T2: Winner-takes-all, changing ranking (the same person cannot win consecutively).

T3: Multiple unequal prizes, same ranking (two or three prizes of different values, not proportional to performance).

T4: Multiple unequal prizes, changing ranking (unequal rewards with enforced rotation of winners).

This design allows causal identification of how different incentive schemes affect motivation and performance when productivity differences are known but immutable.
Experimental Design Details
Not available
Randomization Method
Randomization done in the laboratoryby a computer
Randomization Unit
Individual
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
130 teams of 3 subjects each. Around 33 teams per treatment
Sample size: planned number of observations
400 subjects
Sample size (or number of clusters) by treatment arms
100 subjects per treatment
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Supporting Documents and Materials
IRB

Institutional Review Boards (IRBs)

IRB Name
Zayed University Research Ethics Committee
IRB Approval Date
2025-12-10
IRB Approval Number
ZU25_104_F
Analysis Plan