Alós-Ferrer, Fehr, and Netzer (2018) and Echenique and Saito (2017) study models where response time is a deterministic function of the utility difference. Che and Mierendorff (2016); Hebert and Woodford (2016); Liang and Mu (2019); Liang, Mu, and Syrgkanis (2019); Woodford (2014); Zhong (2019) study dynamic costly optimal information acquisition.
The Stochastic Choice FunctionLet X be the universe of alternatives (actions) and T = R + be time. For every pair of objects {x, y} the analyst observes pairwise stochastic choices and decision times. In the limit as the sample size grows large, the analyst will have access to the joint distribution over which object is chosen and at which time a choice is made. We denote by F xy (t) the probability that the agent makes a choice by time t, and let p xy (t) the probability that the agent picks x conditional on stopping at time t. Throughout, we restrict attention to cases where F has full support and no atoms at time 0, so that F (0) = 0, and we assume that F is strictly increasing with lim t→∞ F (t) = 1. These restrictions imply the agent never stops immediately, that there is a positive probability of stopping in every time interval, and that the agent always eventually stops. We call (p xy , F xy ), the stochastic choice function.An immediate restriction on the stochastic choice function is that the choices of the agent are unaffected by which object we consider to be the first and which object we consider to be the second. This is formally equivalent to p xy (t) ≡ 1 − p yx (t) for all t and F xy ≡ F yx for all x, y ∈ X.Without loss of generality we only consider stochastic choice functions which satisfy this restriction. We also assume that each option is chosen with positive probability 0 < p xy (t) < 1 for all t.