The minority game.
Everyone picks Left or Right at the same time: can you predict where the crowd will go so you end up in the minority?
Original study
- Arthur, W. B. (1994). Inductive reasoning and bounded rationality. American Economic Review, 84(2), 406–411. Source
- Challet, D., & Zhang, Y.-C. (1997). Emergence of cooperation and organization in an evolutionary game. Physica A: Statistical Mechanics and its Applications, 246(3–4), 407–418. Source
- Savit, R., Manuca, R., & Riolo, R. (1999). Adaptive competition, market efficiency, and phase transitions. Physical Review Letters, 82(10), 2203–2206. Source
- Bottazzi, G., & Devetag, G. (2003). A laboratory experiment on the minority game. Physica A: Statistical Mechanics and its Applications, 324(1–2), 124–132. Source
- Płatkowski, T., & Ramsza, M. (2003). Playing minority game. Physica A: Statistical Mechanics and its Applications, 323, 726–734. Source
- Challet, D., Marsili, M., & Zhang, Y.-C. (2004). Minority games: Interacting agents in financial markets. Oxford University Press. Source
- Arechar, A. A., Gächter, S., & Molleman, L. (2018). Conducting interactive experiments online. Experimental Economics, 21(1), 99–131. Source
Our adaptation
A live-room adaptation of Arthur's (1994) El Farol problem and Challet and Zhang's (1997) minority game. A game starts when 9 people gather in a public room (3–200 in private rooms); over 10 rounds each player picks Left or Right within 10 seconds, and others' choices stay hidden until the round ends. Players on the side chosen by fewer people get 1 point; nobody scores on a tie. Choices are collected on the server and results are written on the server when the room ends.
Differences from the original study
- Points are not real money.
- 10 rounds are far shorter than the 100 of laboratory studies.
- Room size varies, and if someone leaves mid-game the count can become even.
Measured variables
The columns of the open data file. List fields are expanded into numbered columns (for example rt_60, est_3); JSON columns contain only numbers and fixed stimulus names.
| Column | Type | Description |
|---|---|---|
group_id | group code | Room code: links rows from the same room; regenerated at random in every release. |
group_size | integer | Number of players in the room. |
points | number | Player's total points (rounds won). |
picks | JSON | Choices over ten rounds (0 = Left, 1 = Right, null = no choice). |
mshare | number | Room's mean minority share over rounds (%; share of players on the winning side, 0 on tied rounds). |
switch_rate | number | Player's rate of switching sides between consecutive valid choices. |
Columns present in every file (14)
row_id | string | Row code. Regenerated at random in every release; it does not identify a person and cannot be matched across releases or experiments. |
experiment | string | Short name of the experiment (URL slug). |
experiment_version | integer | Version of the answer format. For experiments whose format changed, only the current format is published. |
date | YYYY-MM-DD | YYYY-Www | YYYY-MM | Day the answer was given (Istanbul time). If fewer than 5 answers share the same day, language and device, it is coarsened to the ISO week, and to the month if that is still too few. |
date_precision | day | week | month | Precision of the date column. |
lang | tr | en | (boş) | Interface language. Language recording started in the first week of October 2026; for earlier answers it is known only in experiments whose stimuli depend on the language, and empty otherwise. |
device | desktop | mobile | tablet | (boş) | Device class reported by the browser (class only; browser details are neither stored here nor published). |
source | site | embed | Where the answer came from: the balabs site or the experiment embedded on another site. The embedding site is not published. |
mode | free | daily | challenge | race | session | (boş) | Play mode in scored experiments: free play, daily round, challenge, race room, experiment session. Empty for unscored experiments and for older answers that did not store it. |
color_vision | normal | rg | by | contrast | (boş) | In color-based experiments, the color vision mode the participant chose: normal, red-green, blue-yellow or high contrast. Stimuli are generated along different axes per mode, so compare within a mode. Empty for other experiments. |
first_play | 1 | Every row is a participant’s first play of this experiment (always 1). Replays are stored only as leaderboard scores and are not part of the open data. |
seen_before | yes | no | unsure | (boş) | Participant’s own report of whether they had seen this experiment or its known answer before (in experiments that ask). |
duration_s | number | Time from the start of the experiment to submitting the answer, in seconds (measured in the browser, 0.1 s). |
play_score | number | Leaderboard score of the first play (scored experiments; defined on the method card). Empty for unscored experiments. |
Exclusion criteria
Answers to this experiment are never accepted from the browser; they are written on the server from the room's action records only when the room ends. Spectators who joined the room but did not play are not included.
- Only each participant's first answer to this experiment; replays are not included.
- Simulated rows, bots, banned and sample accounts are not included.
- Answers before 3 October 2026 are not included (the first day the open data notice was live).
Scoring
This experiment has no leaderboard score. The in-room score is the number of rounds won.
Version notes
- October 2026
The interface language (lang) started being stored with each answer; for earlier answers it is known only in experiments whose stimuli depend on the language, and empty otherwise.