Gaming or Gambling? On Selection Neglect and Loot Boxes (Additional Treatments II)

Last registered on November 30, 2022


Trial Information

General Information

Gaming or Gambling? On Selection Neglect and Loot Boxes (Additional Treatments II)
Initial registration date
November 28, 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 30, 2022, 4:32 PM EST

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


Primary Investigator

Central European University

Other Primary Investigator(s)

PI Affiliation
University of Bonn
PI Affiliation
University of Münster
PI Affiliation
Heinrich-Heine-University Düsseldorf

Additional Trial Information

In development
Start date
End date
Secondary IDs
Prior work
This trial is based on or builds upon one or more prior RCTs.
Nowadays, many successful video games feature "loot boxes" that, just like gambling, offer random rewards to be used in-game. In 2020 alone such loot boxes generated $15 billion of worldwide revenue. There is an increasing public concern, however, that video game developers design loot boxes in a way to make gamers "overpay" for the typically small chance of getting the reward. We single out two features of loot boxes that might result in gamers overestimating the probability of winning the reward and, consequently, paying too much. First, developers typically do not disclose the odds, but provide gamers only with an interval-censored distribution of rewards. Second, in many games there is a public announcement whenever someone wins a reward, which results gamers observing a selected sample of the reward distribution. In a controlled laboratory experiment, we systematically study the effect of either feature, as well as combinations thereof, on the willigness-to-pay for (monetary) lotteries.
External Link(s)

Registration Citation

Cordes, Simon et al. 2022. "Gaming or Gambling? On Selection Neglect and Loot Boxes (Additional Treatments II)." AEA RCT Registry. November 30.
Experimental Details


We study the willingness-to-pay for and beliefs about monetary lotteries across three treatments that vary how much information subjects receive on the reward distribution.
Intervention Start Date
Intervention End Date

Primary Outcomes

Primary Outcomes (end points)
A subject's willingness-to-pay for different lotteries.
Primary Outcomes (explanation)

Secondary Outcomes

Secondary Outcomes (end points)
A subject's belief about how often (out of 100 draws) the maximum prize of the lottery is realized.
Secondary Outcomes (explanation)

Experimental Design

Experimental Design
In each treatment, subjects state their willingness-to-pay for 5 different monetary lotteries. All lotteries have the following structure: with probability 1 - q, a subject gets 0 Coins; with probability 0.01, a subject gets x Coins; and with probability q - 0.01, a subject gets 10 Coins. (At the end of the experiment, Coins will be converted to Pounds at an exchange rate of 13 Coins = 1 Pounds.) One out of every 6 subjects will be randomly selected to receive a bonus payment based on the subject's willingness-to-pay for one randomly drawn lottery. (The payment will be determined via a BDM mechanism.)

The parameter tuple (x, q) is randomly drawn (without replacement) from {100, 120, 140, 160, 180} x {0.1, 0.2, 0.3, 0.4, 0.5}. In each decision, subjects learn the feasible outcomes x, 10, and 0, but we vary across three treatments how much information they receive on the corresponding probabilities.

Treatment "Control": subjects observe the full reward distribution; that is, they learn the probabilities of receiving each of the three possible outcomes.

Treatment "Joint": subjects learn the probability, q, of receiving at least 10 Coins, and, in addition, they observe the five highest outcomes in a random sample of 400 draws (from the underlying distribution).

Treatment "Nudge": Subjects learn the probability, q, of receiving at least 10 Coins, and, in addition, they observe the five highest outcomes in a random sample of 400 draws (from the underlying distribution). Moreover, on each decision screen, we remind subjects that 10 Coins and x Coins need not be equally likely, and that the sample is not representative of the reward distribution. We also provide them information on the distribution of 10 and x in the last 50 draws.

Before subjects state their willingness-to-pay for a given lottery, they state their belief about the probability with which the lottery pays its highest prize of x Coins. More specifically, subjects answer the following question (using a slider from 0 to 100 times): "Imagine you would play the lottery 100 times. How often do you think would you win x Coins?"

At the end of the experiment, we ask for demographics and experience with loot boxes. We further include the TSCS Self Control Module and the PGSI Gambling Module. We plan to use these additional variables as controls when testing for treatment effects on our outcome variables. And we will further test whether these measures are correlated with our outcome variables.
Experimental Design Details
Randomization Method
Randomization is done by the computer
Randomization Unit
Was the treatment clustered?

Experiment Characteristics

Sample size: planned number of clusters
450 subjects
Sample size: planned number of observations
2250 willingness-to-pay statements and 2250 belief statements
Sample size (or number of clusters) by treatment arms
750 willingness-to-pay statements and 750 belief statements
Minimum detectable effect size for main outcomes (accounting for sample design and clustering)

Institutional Review Boards (IRBs)

IRB Name
German Association for Experimental Economic Research e.V.
IRB Approval Date
IRB Approval Number
No. bK8MbiCk


Post Trial Information

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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