Online Housing Market

TL;DR

This paper explores online housing markets where agents arrive and depart asynchronously, extending classic exchange mechanisms to this setting and analyzing the trade-offs in maintaining efficiency, rationality, and strategy-proofness.

Contribution

It introduces online extensions of serial dictatorship and Gale's top trading cycle mechanisms, analyzing their properties and limitations in dynamic agent environments.

Findings

Achieving all desirable properties simultaneously is impossible online.

Several mechanism variants are proposed, each satisfying different subsets of properties.

The study highlights fundamental trade-offs in online housing market design.

Abstract

This paper studies an online variant of the celebrated housing market problem, where each agent has a single house and seeks to exchange it for another based on her preferences. In this online setting, agents may arrive and depart at any time, meaning that not all agents are present on the housing market simultaneously. I extend the well known serial dictatorship and Gale s top trading cycle mechanisms to this online scenario, aiming to retain their desirable properties such as Pareto efficiency, individual rationality, and strategy proofness. These extensions also seek to prevent agents from strategically delaying their arrival or advancing their departure. I demonstrate that achieving all of these properties simultaneously is impossible in the online context, and I present several variants that achieve different subsets of these properties.