Urban public transit agencies spend billions of dollars each year on workers, durable capital and energy to supply transportation services. During a time of rising concern about climate change, the urban public transit sector has not significantly reduced its carbon footprint. Using data for the...

The U.S. public transit system represents a multi-billion dollar industry that provides essential transit services to millions of urban residents. We study the market for new transit buses that features a set of non-profit transit agencies purchasing buses primarily from a few domestic bus...

Diesel emissions from school buses expose children to high levels of air pollution; retrofitting bus engines can substantially reduce this exposure. Using variation from 2,656 retrofits across Georgia, we estimate effects of emissions reductions on district-level health and academic achievement....

This paper develops a simple model of international trade with intermediation. We consider an economy with two islands and two types of agents, farmers and traders. Farmers can produce two goods, but in order to sell these goods in centralized (Walrasian) markets, they need to be matched with a...