Rationality and Behavior Feedback in a Model of Vehicle-to-Vehicle Communication

TL;DR

This paper compares Bayesian and non-Bayesian models of vehicle-to-vehicle communication, revealing that simplified models can replicate some behaviors but miss critical informational paradoxes, highlighting limitations of standard Bayesian approaches.

Contribution

It introduces a non-Bayesian behavior model and an equilibrium framework that avoids endogenous recursion, demonstrating their equivalence in some aspects and limitations in capturing paradoxes.

Findings

Non-Bayesian model matches Bayesian equilibrium behavior.

Endogenous models reveal informational paradoxes absent in exogenous models.

Simplified models may overlook critical informational phenomena.

Abstract

Vehicle-to-Vehicle (V2V) communication is intended to improve road safety through distributed information sharing; however, this type of system faces a design challenge: it is difficult to predict and optimize how human agents will respond to the introduction of this information. Bayesian games are a standard approach for modeling such scenarios; in a Bayesian game, agents probabilistically adopt various types on the basis of a fixed, known distribution. Agents in such models ostensibly perform Bayesian inference, which may not be a reasonable cognitive demand for most humans. To complicate matters, the information provided to agents is often implicitly dependent on agent behavior, meaning that the distribution of agent types is a function of the behavior of agents (i.e., the type distribution is endogenous). In this paper, we study an existing model of V2V communication, but relax it along two dimensions: first, we pose a behavior model which does not require human agents to perform Bayesian inference; second, we pose an equilibrium model which avoids the challenging endogenous recursion. Surprisingly, we show that the simplified non-Bayesian behavior model yields the exact same equilibrium behavior as the original Bayesian model, which may lend credibility to Bayesian models. However, we also show that the original endogenous equilibrium model is strictly necessary to obtain certain informational paradoxes; these paradoxes do not appear in the simpler exogenous model. This suggests that standard Bayesian game models with fixed type distributions are not sufficient to express certain important phenomena.