This paper assesses the causal impact of greater market access on demographic transition during the latter half of the 19th century in the United States. We construct new measures of fertility changes and measures of railroad access at the county level from 1850 - 1890. We are able to document...

H. Gregg Lewis did fundamental research outlining the economic effects of trade unions and considering how to measure them carefully. He also laid out the theory of the supply and demand for labor in careful detail that has underlain economists' thinking about these outcomes. Aside from...

Examining the most heavily-cited publications in labor economics from the early 1990s, I show that few of over 3000 articles citing them directly replicates them. They are replicated more frequently using data from other time periods and economies, so that the validity of their central ideas has...

Using evidence from recent work on truckers and disaggregated older data prior researchers did not have, we revisit a classic topic and find some new answers. We focus on differentials in average annual earnings at the firm level among mileage-paid over-the-road tractor-trailer drivers ("road...

In New York City (NYC), it has been a common complaint that it is difficult to find a taxi in the rain. Using all Uber rides in NYC from April to September 2014 and January to June 2015, we show that the number of Uber rides is significantly correlated with whether it rained. The number of Uber...

Nowcasting has been a challenge in the recent economic crisis. We introduce the Toll Index, a new monthly indicator for business cycle forecasting and demonstrate its relevance using German data. The index measures the monthly transportation activity performed by heavy transport vehicles across...

We develop a product market theory that explains why firms invest in general training of their workers. We consider a model where firms first decide whether to invest in general human capital, then make wage offers for each others' trained employees and finally engage in imperfect product market...

Following market liberalisation, the vehicle population in China has increased dramatically over the past few decades. This paper examines the causal impact of the opening of a heavily used high speed rail line connecting two megacities in China in 2015, Chengdu and Chongqing, on air pollution....