Response time and utility

• “Response time” is the time an agent takes to make a decision.
• We propose an axiomatic model that predicts choices and response time.
• The model captures the (empirically robust) tendency of agents to take longer time when they choose between options with similar utilities.
• Our axioms represent non-parametric tests of the theory. The axioms are testable using finite data on binary choices and response times.

Response time is the time an agent needs to make a decision. One fundamental finding in psychology and neuroscience is that, in a binary choice, there is a monotonic relationship between the response time and the difference between the utilities of the two options. We consider situations in which utilities are not observed, but rather inferred from revealed preferences: meaning they are inferred from subjects’ choices. Given data on subjects’ choices, and the time to make those choices, we give conditions on the data that characterize the property that response time is a monotonic function of utility differences.