BDM mechanism design choice impact on valuation elicitation

Last registered on February 19, 2026

Pre-Trial

Trial Information

General Information

Title
BDM mechanism design choice impact on valuation elicitation
RCT ID
AEARCTR-0017900
Initial registration date
February 17, 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 19, 2026, 7:37 AM EST

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

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Primary Investigator

Affiliation
Texas &MUniversity

Other Primary Investigator(s)

PI Affiliation
Agricultural University of Athens
PI Affiliation
Texas A&M University

Additional Trial Information

Status
In development
Start date
2026-02-23
End date
2026-02-25
Secondary IDs
Prior work
This trial is based on or builds upon one or more prior RCTs.
Abstract
The incentive compatibility of the Becker-DeGroot-Marschak (BDM) mechanism implies valuations should not depend on the market offer range or where the induced value falls within that range. In our first experiment (AEARCTR-0016635), varying the support set's upper bound while holding the induced value fixed produces monotonic increases in mean willingness to accept. Risk preferences are not correlated with the size of the shift as hypothesized. This second experiment varies the induced value within a fixed range to test whether responses shift with value location. A similar shift in this environment implies a mechanical adjustment to the location of the induced value with respect to the range. Taken together, the experiments evaluate whether valuations are sensitive to response scale width and value placement, highlighting context dependence in a theoretically incentive-compatible mechanism.

Registration Citation

Citation
Drichoutis, Andreas, Benjamin Horlick and Marco Palma. 2026. "BDM mechanism design choice impact on valuation elicitation." AEA RCT Registry. February 19. https://doi.org/10.1257/rct.17900-1.0
Experimental Details

Interventions

Intervention(s)
We implement the BDM mechanism in three repeated rounds to elicit willingness-to-accept for an induced value item. The value of the item is exogenously changed each round to $3, $6, and $9 in random order. The distribution of possible offers is fixed across rounds and ranges from $0 to $12.
Intervention Start Date
2026-02-23
Intervention End Date
2026-02-25

Primary Outcomes

Primary Outcomes (end points)
Individual willingness-to-accept values in each treatment
Primary Outcomes (explanation)
We use the elicited values to test whether moving the relative placement of the induced value within the support set results in changes to the distribution of willingness-to-accept values. Please see the Analysis Plan for more details.

Secondary Outcomes

Secondary Outcomes (end points)
N/A
Secondary Outcomes (explanation)
Our survey maintains the same risk preference elicitation tasks from the initial experiment to minimize changes to the procedure; however, we omit the measures as secondary outcomes in this follow-up because our Analysis Plan does not include the corresponding heterogeneity analyses.

Experimental Design

Experimental Design
Our experiment is divided in two parts. In the first part, subjects are asked to submit offers to sell a card to the experimenter in three repeated rounds that vary within-subjects the value of the card at $3, $6 or $9 in random order. We fix the support set with lower and upper bounds of $0 and $12, respectively. At the end of the experiment, one of the three rounds is selected for realization. Following the BDM mechanism task, we ask respondents about their strategy selection process and give them the opportunity to explain a rationale in an open response format.

The second part of the experiment elicits subjects' risk preferences. We implement the static version of the BRET (Crosetto & Filippin, 2013). Subjects complete the task once with no practice rounds. The task presents participants with 100 boxes arranged in a 10x10 grid. One randomly selected box holds a bomb while the other 99 contain a reward of $0.10. Each subject then chooses how many boxes to collect. If the bomb is among the selected quantity of boxes, the participant receives no additional earnings from the task; otherwise, we add the amount of money inside the collected boxes to the subject's total payoff.

As a secondary measure of risk preferences, we also employ the self-reported risk question from the German Socio-Economic Panel survey (Dohmen et al., 2011).
Experimental Design Details
Not available
Randomization Method
Computer; all randomizations are performed within Qualtrics.
Randomization Unit
Treatment order is randomized at the individual level.
Was the treatment clustered?
No

Experiment Characteristics

Sample size: planned number of clusters
75 individuals
Sample size: planned number of observations
75 individuals
Sample size (or number of clusters) by treatment arms
225 observations (75 individuals and 3 rounds)
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)
We utilize the data from similarly parameterized treatments in Drichoutis et al. (2025) to estimate the inputs to our power calculations. With an induced value of $3.00, the average offer shifted from $2.701 with a support set upper bound of $4.00 to $3.158 with a support set upper bound of $6.00. Each subject participated in both treatments. The pooled standard deviation of the two offer distributions was 0.895. In our power analysis presented below, we conservatively assume a between-treatment correlation of 0.3, compared to the actual observed correlation of 0.501. We employ the asymptotic relative efficiency (ARE) method in our power calculation which estimates the sample size required under a parametric t-test at a given power level and converts the result to the sample size required by the nonparametric Wilcoxon signed-rank test that we use to test our primary hypothesis (Faul et al., 2009). The sample size required under a t-test is then 51. The ARE of the Wilcoxon test is approximately 0.955, implying a sample size of 53 (Faul et al., 2009). Utilizing the actual observed correlation value of 0.509 yields a sample size of 39. As additional reference points, we conduct the same analysis using the results from our first experiment (AEARCTR-0016635). With an induced value of $3.00, mean willingness to accept increased from $3.413 in the $6.00 support range treatment to $5.451 with a pooled standard deviation of 2.069 and a between-treatment correlation of 0.42, yielding an effect size of 0.823 and sample size requirement of 15. Comparing the $6 treatment against the $4 treatment, we observe a mean shift of $0.737, a pooled standard deviation of 0.917, and correlation of 0.52, resulting in an effect size of 0.792 and sample size requirement of 16. Reducing the correlation to a hypothetical 0.25 increases the minimum sample size range to 17-22 subjects. In the interest of conservatism, we adopt the larger threshold of 53 subjects determined for the Phase 1 study. Accordingly, we target a sample size of 75 participants, representing the minimum threshold grossed up for incomplete or otherwise unusable responses.
Supporting Documents and Materials

Documents

Document Name
Survey Instrument
Document Type
survey_instrument
Document Description
File
Survey Instrument

MD5: c5f299dc30baa67f7e5ba1a8ce2bfd94

SHA1: 3e34f580aa8daeedda162421424df232d507fac7

Uploaded At: February 17, 2026

Document Name
IRB Protocol
Document Type
irb_protocol
Document Description
File
IRB Protocol

MD5: 1e6e25873169ecb6906069f158262219

SHA1: 32082fab9b244e56d1560a538d18a70d971af273

Uploaded At: February 17, 2026

IRB

Institutional Review Boards (IRBs)

IRB Name
Texas A&M Institutional Review Board
IRB Approval Date
2026-02-16
IRB Approval Number
STUDY2025-0840 (MOD00003539)
Analysis Plan

Analysis Plan Documents

BDM Design Elements Pre-Analysis Plan

MD5: ca0cf078259f4a6bf5e25552cb47612d

SHA1: 5a56f28469210d228e36835c5fec307c7a363686

Uploaded At: February 17, 2026