Behavioral games
Run an Ultimatum Game
Study offers and acceptance decisions when rejection eliminates the proposed split.
The basic idea
The proposer offers a division of an endowment and the responder accepts or rejects it. Acceptance implements the split; rejection gives both players the configured rejection outcome, typically zero. Sequential visibility is essential because the responder must see the offer without seeing hidden future information.
Have a model propose a split to a human responder, then reverse the actor types in a separate randomized condition.
How to do it
- 1
Assign proposer and responder seats and set the shared endowment.
- 2
Confirm that the responder sees the offer needed to decide while unrelated current-round choices remain hidden.
- 3
Set repetition, feedback, labels, and actor composition before distributing links.
- 4
Report offers, acceptance rates, proposer and responder payoffs, and order or actor-type contrasts.
What to watch for
- Acceptance thresholds and offer behavior are different outcomes.
- Swapping actor types without randomization can confound role and actor effects.
- Custom rejection payoffs or side payments create a different strategic problem.
What a useful result looks like
The record links each proposal to its response and resolved split without exposing the responder to information unavailable under the configured protocol.