arXiv subjects

Evan Sadler

Publications and source records attributed to Evan Sadler.

3 recordsLinked to original sources

arXiv2026

A Theory of Network Games Part 1: Utility Representations

We provide interpretable axiomatic foundations for utilities used in network games and identify several principled generalizations. First, we demonstrate that a ubiquitous feature of network games, bilateral strategic interactions, is equivalent to having player utilities that are additively separable across opponents. Common utilities based on a linear aggregate of opponent actions are strategically equivalent to additively separable utilities. Moreover, assuming real-valued actions, we show that a constant rate of substitution between opponents implies a utility that is linear in opponent actions. Finally, we identify precise conditions--linear best replies and midpoint indifference--that pin down the classic linear-quadratic utility.

econ.TH↗

arXiv2023

On the Difficulty of Characterizing Network Formation with Endogenous Behavior

Bolletta (2021, Math. Soc. Sci. 114:1-10) studies a model in which a network is strategically formed and then agents play a linear best-response investment game in it. The model is motivated by an application in which people choose both their study partners and their levels of educational effort. Agents have different one-dimensional types $\unicode{x2013}$ private returns to effort. A main result claims that pairwise Nash stable networks have a locally complete structure consisting of possibly overlapping cliques: if two agents are linked, they are part of a clique composed of all agents with types between theirs. We offer a counterexample showing that the claimed characterization is incorrect, highlight where the analysis errs, and discuss implications for network formation models.

econ.TH↗

arXiv2021

Games on Endogenous Networks

We study network games in which players choose both the partners with whom they associate and an action level (e.g., effort) that creates spillovers for those partners. We introduce a framework and two solution concepts, extending standard approaches for analyzing each choice in isolation: Nash equilibrium in actions and pairwise stability in links. Our main results show that, under suitable order conditions on incentives, stable networks take simple forms. The first condition concerns whether links create positive or negative payoff spillovers. The second concerns whether actions are strategic complements to links, or strategic substitutes. Together, these conditions yield a taxonomy of the relationship between network structure and economic primitives organized around two network architectures: ordered overlapping cliques and nested split graphs. We apply our model to understand the consequences of competition for status, to microfound matching models that assume clique formation, and to interpret empirical findings that highlight unintended consequences of group design.

econ.TH↗