JOB MARKET PAPER
Fragmented Markets and the Proliferation of Small Firms: Evidence from Mom-and-Pop Shops in Mexico joint with Daniel Ramos-Menchelli
Developing countries are characterized by the prevalence of small firms in the retail sector. We explain this phenomenon through a spatial model in which high transport costs lead to small effective market sizes and, consequently, to the proliferation of smaller and lower quality firms. We show that low costs of entry are key for this result. By obtaining a new, confidential panel of firm-level data surveying the universe of mom-and-pop shops in Mexico, we test the implications of our model. We exploit the deregulation of the Mexican gasoline market in 2017 as an exogenous shock on consumer transport costs. Where gas prices increased, the number of mom-and-pop shops differentially increased while their average size and quality fell. We give evidence of fragmentation and localized demand as the mechanism behind these effects. With our estimated model, we evaluate the welfare consequences of a licensing program in Mexico City which increased costs of entry for mom-and-pop shops. We show there are modest efficiency gains from having less stores in the market.