We propose a theory-inspired measure of the accessibility of a city's center: the size of the surrounding area from which it can be reached within a specific time. Using publicly available optimal-routing software, we compute these "accessibility zones" for the 109 largest US and European...

How large are the benefits of transportation infrastructure projects, and what explains these benefits? To shed new light on these questions, this paper uses archival data from colonial India to investigate the impact of India's vast railroad network. Guided by four predictions from a general...