Productivity spillovers are often cited as a reason for geographic specialization in production. A large literature in medicine documents specialization across areas in the use of surgical treatments, which is unrelated to patient outcomes. We show that a simple Roy model of patient treatment...

In a widely cited study, Chetty, Friedman, and Rockoff (2014a; hereafter CFR) evaluate the degree of bias in teacher value-added estimates using a novel "teacher switching" research design with data from New York City. They conclude that there is little to no bias in their estimates. Using the same...

The introduction of legalized abortion in the early 1970s led to dramatic changes in fertility behavior. Some research has suggested as well that there were important impacts on cohort outcomes, but this literature has been limited and controversial. In this paper, we provide a framework for...

We use six years of data on student test performance to evaluate the effectiveness of certified, uncertified, and alternatively certified teachers in the New York City public schools. On average, the certification status of a teacher has at most small impacts on student test performance....

In his classic 1957 study of hybrid corn, Griliches emphasized the importance of economic incentives and profitability in the adoption of new technology, and this focus has been continued in the economics literature. But there is a distinct literature with roots in sociology emphasizing the...

There is little causal evidence on the effect of economic and policy outcomes on voting behavior. This paper uses randomized outcomes from a school choice lottery to examine if lottery outcomes affect voting behavior in a school board election. We show that losing the lottery has no significant...

Inefficiency in the U.S. health care system has often been characterized as "flat of the curve" spending providing little or no incremental value. In this paper, we draw on macroeconomic models of diffusion and productivity to better explain the empirical patterns of outcome improvements in...

Do not-for-profit hospitals provide better care than for-profit hospitals? We compare patient outcomes in for-profit and not-for-profit hospitals between 1984 and 1994 using a new method for estimating differences across hospitals that yields far more accurate estimates of hospital quality than...

We estimate the impact of changes in abortion access in the early 1970s on the average living standards of cohorts born in those years. In particular, we address the selection inherent in the abortion decision: is the marginal child who is not born when abortion access increases more or less...

This paper investigates the precision of conventional and unconventional estimates of the natural rate of unemployment (the 'NAIRU'). The main finding is that the NAIRU is imprecisely estimated: a typical 95% confidence interval for the NAIRU in 1990 is 5.1% to 7.7%. This imprecision obtains...