Competition and Bribery in Auction Experiments

Last registered on November 17, 2022


Trial Information

General Information

Competition and Bribery in Auction Experiments
Initial registration date
November 12, 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
November 17, 2022, 3:45 PM EST

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



Primary Investigator

BI Norwegian Business School

Other Primary Investigator(s)

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial does not extend or rely on any prior RCTs.
Does competition affect the impact of bribery on auction allocation and revenue? Bribery auctions are a collection of auction models where the auctioneer extracts a share of the seller revenue by soliciting bribes from potential bidders. This study aims to experimentally test this effect of competition in reducing the ineffeciency of bribery. To do this I introduce a two stage auction game. In the first stage the players can bid for the right of first refusal (ROFR) followed by an entry decision. Stage two is a standard first price auction (FPA) auction for the good with ROFR assigned to the winner of the first stage. I then vary the degree of competition in the first stage. This model is designed with experimental testing in mind, and thus has unique symmetric equilibria for any level of competition.
External Link(s)

Registration Citation

McKay, Thomas. 2022. "Competition and Bribery in Auction Experiments." AEA RCT Registry. November 17.
Experimental Details


This study is economics lab experiment testing a multistage bribery auction game when varying the degree of competition in bribery.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
The level of entry in each treatment.
Primary Outcomes (explanation)
There are three players in each auction game, thus entry will be the mean number of entrants measured at the block level

Secondary Outcomes

Secondary Outcomes (end points)
Efficiency, Bribery Auction Price, Goods Auction Price
Secondary Outcomes (explanation)
Efficiency is constructed as 1 when the subject with the highest valuation is allocated the good, and zero otherwise. Bribery Auction Price is the mean price in the bribery auction, measured at the block level. Goods Auction Price is the mean price in the goods auction, measured at the block level.

Experimental Design

Experimental Design
This is a 3x1 study with between subjects design. Each game consists of 3 subjects who participate as bidders, while the seller and auctioneer are automated. The difference between treatments is the number of players competing in the first stage (3, 2 or 1). In addition, when there would be only a single subject in the bribery auction, I randomly assign ROFR to a random subject, as having a single bidder in an auction complicates the implementation and may be confusing for subjects. My design thus has three treatments. In treatment PC all subjects compete in the bribery stage. In treatment IC, 2 of the 3 subjects are randomly selected to participate in the bribery stage. In treatment NC, there is no bribery stage and instead the ROFR is assigned to a random subject.
Experimental Design Details
see prestudy plan
Randomization Method
Random assignment to treatment, and blocked lab design in groups of 6 with random rematching within blocks.
Randomization Unit
Block of 6 subjects.
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
30 Blocks
Sample size: planned number of observations
180 participants, 1200 Auction games.
Sample size (or number of clusters) by treatment arms
10 blocks per treatment, 30 blocks total
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
Power analysis on two sided rank sum test based on pilot data indicated that 7 blocks were required in order to reach power of 90% for primary variable. Since I chose blocks of 10 power is thus 98.3%

Institutional Review Boards (IRBs)

IRB Name
IRB Approval Date
IRB Approval Number
Analysis Plan

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Post Trial Information

Study Withdrawal

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Is the intervention completed?
Data Collection Complete
Data Publication

Data Publication

Is public data available?

Program Files

Program Files
Reports, Papers & Other Materials

Relevant Paper(s)

Reports & Other Materials