Defining Geographic Markets with Willingness to Travel Circles

Abstract

Issues of spatial competition play a key role in many antitrust matters in terms of both defining relevant markets and evaluating competitive effects. One area where this is particularly important is in retail competition. While detailed data for conducting empirical analyses is available in many retail industries, it is often the case that practitioners must define markets, at least preliminarily, under limited information. In this paper, we develop techniques for aiding in defining markets involving spatial competition under limited information.

Keywords: antitrust, spatial competition, retail competition, actual loss, critical loss, SSNIP, significant non-transitory increase in price, HMT, hypothetical monopolist

JEL Classification: D83, L40, L41