Over the recent years, a new interest has started to emerge on studying the distribution of economic activity across space, on the effects of the rise of market concentration, and the rise of superstar firms in the economy. In my main project I explore a channel overlooked by these two literatures, studying how access to transport infrastructures can benefit disproportionately large exporting firms. By locating in proximity to a transport infrastructure, these firms would significantly reduce the costs they face, thanks to a reduction in their marginal costs, due to the decrease of transport charges. This would not translate to a symmetric reduction of prices due to imperfect competition. Smaller firms would benefit less from this channel, given the lower quantity of output that they produce. Furthermore, the higher the level of spatial frictions in the economy, the more relevant this mechanism will be. Unlike standard results in the trade and geography literature, in this setting trade openness and increases in market access could then have an anti-competitive effect for the economy, according to the size of firms active in the market.

I first provide evidence in support of this hypothesis using Indian plant-level data from 2000 to 2010, together with information on the location of transport infrastructures. The next steps of my analysis would be to observe how the channel I described affected the growth pattern of the locations I study. I plan to extend this analysis also to developed economies, using highdetailed administrative firm level data from France, from which I already received access to. I also propose a theoretical framework that describes the mechanism in act, featuring heterogeneous firms with market power, coming from imperfect competition, and that can choose where to locate, in relation to the presence of a transport infrastructure in the area. Due to local costs, only the most productive companies would choose to relocate and benefit from the transport infrastructure channel.