English

Machine-Learning to Trust

Theoretical Economics 2025-11-17 v2

Abstract

Can players sustain long-run trust when their equilibrium beliefs are shaped by machine-learning methods that penalize complexity? I study a game in which an infinite sequence of agents with one-period recall decides whether to place trust in their immediate successor. The cost of trusting is state-dependent. Each player's best response is based on a belief about others' behavior, which is a coarse fit of the true population strategy with respect to a partition of relevant contingencies. In equilibrium, this partition minimizes the sum of the mean squared prediction error and a complexity penalty proportional to its size. Relative to symmetric mixed-strategy Nash equilibrium, this solution concept significantly narrows the scope for trust.

Keywords

Cite

@article{arxiv.2507.10363,
  title  = {Machine-Learning to Trust},
  author = {Ran Spiegler},
  journal= {arXiv preprint arXiv:2507.10363},
  year   = {2025}
}
R2 v1 2026-07-01T04:00:05.115Z