In this paper I analyze GMM estimation when the sample is not a random draw from the population of interest. I exploit auxiliary information, in the form of moments from the population of interest, in order to compute weights that are proportional to the inverse probability of selection. The...

We examine the impact of Artificial Intelligence (AI) on productivity in the context of taxi drivers. The AI we study assists drivers with finding customers by suggesting routes along which the demand is predicted to be high. We find that AI improves drivers' productivity by shortening the...

Which Americans experience the worst infrastructure? What are the costs of living with that infrastructure? We measure road roughness throughout America using vertical acceleration data from Uber rides across millions of American roads. Our measure correlates strongly and positively with other...

We examine whether ridesharing provides a meaningful transportation alternative for those who require ongoing healthcare. Specifically, we combine variation in UberX entry across the U.S. with the Treatment Episode Data Set to estimate the effect of ridesharing on admissions to substance use...

Firms invest in scientific research to increase their chances of landing lucrative procurement contracts with the U.S. government. This is an important, but understudied channel through which the government encourages corporate research, particularly when other market mechanisms are...

We study Medicare's competitive bidding program (CBP) for durable medical equipment (DME). We exploit Medicare claims data to examine both prices and utilization, focusing on continuous positive airway pressure (CPAP) devices to treat sleep apnea. We find that spending falls by 47.2% percent...

It is claimed that many regulatory rules enforce inefficiencies in order to achieve the appearance of cost control. We assess the importance of these claims by measuring the effect of New York state's compulsory multiple contractor law on the cost of public construction in New York City....

Adequate wages are an important tool to shield public officials from special interests and corruption. But what is the equilibrium effect of higher wages in the presence of criminal pressure groups, who use both bribes and violence? By means of a regression discontinuity design, we show that an...

More than 17 percent of households in American central cities live in poverty; in American suburbs, just 7.4 percent of households live in poverty. The income elasticity of demand for land is too low for urban poverty to be the result of wealthy individuals' wanting to live where land is cheap...

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...