What explains the current low rate of employment in the US? While there has been substantial debate over this question in recent years, we believe that considerable added insight can be derived by focusing on changes in the labor market at the turn of the century. In particular, we argue that in...

One of the great puzzles of Sub-Saharan African economic history is that wheeled transportation was barely used prior to the colonial period. Instead, head porterage was the main method of transportation. The consensus among historians is that this was a rational adaption to the underlying...

I examine the relationship across diseases between the long-run growth in the number of publications about a disease and the change in the age-adjusted mortality rate from the disease. The diseases analyzed are almost all the different forms of cancer, i.e. cancer at different sites in the body...

When do scientists and other knowledge workers organize into collaborative teams and why do they do so for some projects and not others? At the core of this important organizational choice is, we argue, a tradeoff between the productive efficiency of collaboration and the credit allocation that...

Globalization of scientific and technological knowledge has reduced the US share of world scientific activity; increased the foreign-born proportion of scientists and engineers in US universities and in the US labor market; and led to greater US scientific collaborations with other countries....

Firms play a central role in the selection, sponsorship, and employment of skilled immigrants entering the United States for work through programs like the H-1B visa. This role has not been widely recognized in the literature, and the data to better understand it have only recently become...

We investigate the effect of the vintage (year of FDA approval) of the prescription drugs used by an individual on his or her survival and medical expenditure. When we only control for age, sex, and interview year, we estimate that a one-year increase in drug vintage increases life expectancy by...

This paper examines whether an intra-household externality prevents adoption of a technology with substantial implications for population health and the environment: improved cookstoves. Motivated by a model of intra-household decision-making, the experiment markets stoves to husbands or wives...

Research on intellectual property has focused on formal legally recorded rights that we call deeded, most often measured by granted patents. Meanwhile, other "defacto" IP (mainly purposive secrecy and natural excludability) has become more important because of the increasing closeness of...

We report the results of a randomized experiment testing impacts of subsidies for modern agricultural inputs in rural Mozambique. One-time provision of a voucher for fertilizer and improved seeds leads to substantial increases in fertilizer use, which persist through two subsequent agricultural...