Urban outputs, from economy to innovation, are known to grow as a power of a city’s population. But, since large cities tend to be central in transportation and communication networks, the effects attributed to city size may be confounded with those of intercity connectivity. Here, we map...

The housing affordability issue in mega-cities creates a significant job-housing mismatch and undermines productive new business creation. This paper focuses on Beijing and investigates whether improved accessibility via the subway network helps new firms benefit from agglomeration economies...

Using firm birth records and startup data matched with cities' characteristics, this paper analyzes nearly 300 prefecture-level cities to examine the role of human capital and market access in shaping the economic geography of innovation-driven entrepreneurship in China. We document strong...

Throughout the imperial era, defensive walls surrounded Chinese cities. Although most city walls have vanished, the cities have survived. We analyze a sample of nearly 300 prefectural-level cities in China, among which about half historically had city walls. We document that cities that had...

Using unique data that track college students' performance over multiple high-stakes tests, we study the impact of transitory random disturbances to student cognitive performance and a minimum-passing-score policy on access to graduate education. Exploiting thermal inversions as an instrumental...

Throughout the imperial era, defensive walls surrounded Chinese cities. Although most city walls have vanished, the cities have survived. We analyze a sample of nearly 300 prefectural-level cities in China, among which about half historically had city walls. We document that cities that had...

Location-based social media data is, increasingly, an important facilitator of exploring the movement of goods and people in and between countries across the globe. Typical examples include Twitter, Facebook, Foursquare. As with all social media data outputs, the fundamental value of...

Fine particle pollution is a major public health concern in China. This paper assesses China's potential population exposure to PM2.5 at the subdistrict level, the smallest census unit with public information. Using both ground-based measurements and satellite-based Aerosol Optical Depth...

Location-based social media data is, increasingly, an important facilitator of exploring the movement of goods and people in and between countries across the globe. Typical examples include Twitter, Facebook, Foursquare. As with all social media data outputs, the fundamental value of...