Human Oversight of AI Redistributive Decisions - Study 2

Last registered on August 27, 2026

Pre-Trial

Trial Information

General Information

Title
Human Oversight of AI Redistributive Decisions - Study 2
RCT ID
AEARCTR-0019498
Initial registration date
August 26, 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
August 27, 2026, 12:55 PM EDT

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

Locations

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Primary Investigator

Affiliation
Alma Mater Studiorum - Università di Bologna

Other Primary Investigator(s)

Additional Trial Information

Status
In development
Start date
2026-08-27
End date
2027-03-01
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Abstract
Artificial intelligence is increasingly integrated into high-stakes decisions—investment, hiring, healthcare, military targeting—making human oversight both practically important and increasingly mandated by regulation. Whether people supervise an autonomous artificial agent differently from another human is therefore a crucial question: excessive scrutiny undermines the efficiency gains that motivated AI integration, while overreliance defeats the purpose of the human-in-the-loop.

This project investigates whether individuals exhibit AI aversion when overseeing decisions with real consequences for others, and disentangles two mechanisms: the black-box effect, arising from uncertainty about the AI's decision-making process, and intrinsic AI aversion, a reluctance to rely on algorithmic judgment. In a completed first study (pre-registration at https://www.socialscienceregistry.org/trials/16680), impartial reviewers oversee redistributive decisions made by a human or an AI spectator under incomplete information. In that context, I find no evidence of AI aversion: reviewers are no more likely to overrule an AI's decision than a human's, and beliefs about the AI's decision-making process do not affect intervention.

That design tests both mechanisms at once. The second study, pre-registered here, focuses on intrinsic AI aversion: reviewers now observe the source of inequality before deciding, so an allocation that conflicts with their fairness ideal is unambiguously unfair, and any difference between overseeing a human and overseeing an AI can be attributed to a reluctance—or a preference—to defer to algorithmic judgment per se.
External Link(s)

Registration Citation

Citation
Paoli, Damiano. 2026. "Human Oversight of AI Redistributive Decisions - Study 2." AEA RCT Registry. August 27. https://doi.org/10.1257/rct.19498-1.0
Experimental Details

Interventions

Intervention(s)
Participants evaluate redistributive allocations that determine other people’s payoffs. Each allocation is labeled as being made by either a human or an AI system. Participants can either accept the allocation or pay a small fee to obtain additional information and revise it. The intervention is the different nature of the decision-maker (human vs AI) whose choice is evaluated.
Intervention Start Date
2026-08-27
Intervention End Date
2026-09-12

Primary Outcomes

Primary Outcomes (end points)
The main outcome is the intervention rate.
Intervene(i,a): dummy variable equal to 1 if the reviewer decides to pay the fee and change the allocation to the alternative one, and 0 otherwise. The choice set is binary, so there is no intensive margin: intervention deterministically switches the allocation from (4,0) to (2,2) or vice versa. I collect one observation for each combination (a) of source of inequality and earnings allocation (Merit×(4,0), Merit×(2,2), Luck×(4,0), Luck×(2,2)) through the strategy method, and each reviewer (i) is exposed to both treatment conditions (human and AI spectator), for eight observations per reviewer.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
Realized-oversight measures. The strategy method exposes every reviewer to the four criterion–allocation combinations with uniform frequency, whereas realized spectator decisions are not distributed uniformly. Reweighting each reviewer's eight responses by the empirical frequency of each cell among the realized decisions of spectators of the corresponding type, I report by spectator type: the implied intervention rate, the average fee paid per reviewer, the share of final allocations that differ from the reviewer's fairness ideal, and the share of worker pairs left with unequal earnings.

Fairness view. Each reviewer is classified as egalitarian, meritocratic, libertarian, or other from the two decisions she made as a spectator.

Spectator redistribution decisions, by spectator type and source of inequality.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
The experiment has three parts. First, workers earn money in a real-effort task. Second, spectators decide how to redistribute earnings within a randomly drawn worker pair. Third, reviewers observe a spectator's decision and decide whether to pay a fee to change the allocation. Workers are then paid based on the final allocation. The study focuses on reviewers' decisions; workers and spectators create a consequential economic environment. Unlike the first study, reviewers act under complete information: they observe the source of inequality before deciding.

Workers. 600 workers are recruited on Prolific. After a real-effort task they are randomly paired; in each pair one worker receives an additional 4 USD, determined either by Merit (higher performance) or by Luck (random draw), with equal probability across pairs. They are informed that a third party (the spectator) will see the initial earnings and the criterion and may redistribute earnings within the pair, and that a reviewer may subsequently change the spectator's allocation.

Spectators. There are two spectator types: human (300 participants recruited on Prolific, paid a fixed 5 USD) and AI (300 independent artificial agents). Both receive identical instructions and information. Spectators face a binary choice: leave the unequal allocation (4,0) or split the earnings evenly (2,2). Each spectator decides for two pairs, one in the Merit condition and one in the Luck condition, in randomized order.

Reviewers. The same 300 human participants act as reviewers immediately after their spectator decisions, within the same session. They observe the earnings allocation, the source of inequality (Merit or Luck), and the spectator's type (human or AI), and choose between accepting the allocation and paying a fixed fee of 0.30 USD, deducted from their own earnings, to change it to the alternative allocation. Choices are elicited with the strategy method over the four criterion–allocation combinations, for both spectator types, so each reviewer decides eight times. One of each participant's ten decisions (two as spectator, eight as reviewer) is randomly selected for payment and is consequential for a pair of workers. Participants remain anonymous and are never matched to their own spectator decisions.
Experimental Design Details
Not available
Randomization Method
Randomization is done through the experimental software (oTree).
Randomization Unit
Randomization happens at the individual level. The two spectator-type blocks are presented in randomized order, in balanced blocks: half of the reviewers (150) first evaluate the allocations made by human spectators and then those made by AI spectators; the other half face the opposite order. Within each block, the order of the four criterion-allocation combinations is randomized.
Was the treatment clustered?
Yes

Experiment Characteristics

Sample size: planned number of clusters
300 individuals, acting first as spectators and then as reviewers. The sample is representative of the U.S. population in terms of sex, age, and political affiliation, as determined by Prolific's representative sample distribution.
Sample size: planned number of observations
2,400 reviewer observations = 300 individuals × 4 criterion-allocation combinations × 2 spectator types.
Sample size (or number of clusters) by treatment arms
150 participants (600 observations) with AI spectators first, 150 participants (600 observations) with human spectators first (between-subjects).
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Calibrated on the first study's realized moments: baseline intervention rate p = 0.326 and intra-reviewer correlation of the intervention decision rho = 0.169. With 300 reviewers contributing k = 4 decisions per treatment, the design effect is 1.51 and the between-subjects minimum detectable effect is 9.3 percentage points (29% of the baseline rate) at alpha = 0.05 and power = 0.80. The within-subject comparison, which uses all eight decisions per reviewer, yields a 4.9 percentage-point MDE (15% of the baseline).
Supporting Documents and Materials

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IRB

Institutional Review Boards (IRBs)

IRB Name
Comitato di Bioetica Alma Mater Studiorum - Università di Bologna
IRB Approval Date
2025-05-22
IRB Approval Number
0153983
Analysis Plan

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