The United States first adopted immigration quotas for “undesirable” nationalities in 1921 and 1924 to stem the inflow of low-skilled Eastern and Southern Europeans (ESE). This paper investigates whether these quotas inadvertently hurt American science and invention. Detailed biographic data on the birth place, as well as immigration, education, and employment histories of more than 80,000 American scientists reveal a dramatic decline in the arrival of ESE-born scientists after 1924. An estimated 1,170 ESE-born scientists were missing from US science by the 1950s. To examine the effects of this change on invention, we compare changes in patenting by US scientists in the pre-quota fields of ESE-born scientists with changes in other fields in which US scientists were active inventors. Methodologically, we apply k-means clustering to scientist-level data on research topics to assign each scientists to a research field, and then compare changes in patenting for the pre-quota fields of ESE-born US scientists with the pre-quota fields of other US scientists. Baseline estimates indicate that the quotas led to 68 percent decline in US invention in ESE fields. Decomposing this effect, we find that the quotas reduced not only the number of US scientists working in ESE fields, but also the number of patents per scientist. Firms that had employed ESE-born immigrants before the quotas experienced a 53 percent decline in invention. The quotas damaging effects on US invention persisted into the 1960s.
How do children affect scientific productivity and promotions? We investigate this question using rich biographical data - linked with publications - for 83,000 American scientists in 1956. These data reveal that mothers have a unique life cycle pattern of productivity. Publications by mothers decline in their early 30s, around the birth of their first child, and recover roughly five years later in their late 30s. Mothers publish most in their early 40s while other scientists peak in their 30s. Event studies, which compare the effect of children on married men and women, show that children reduce the productivity of mothers but not fathers. Gender differences in the impact of children are particularly pronounced for academic couples. Differences in the timing of productivity have important implications for promotions. Just 27% of mothers who are academic scientists achieve tenure, compared with 48% of fathers and 46% of women without children. While publications buy other scientists peak around tenure, mothers publish more after tenure.
McCarthy and the Red-ucators: Effects of Political Persecution on Science (with Sahar Parsa). Slides.
This paper examines the effects of political persecution during McCarthyism on American science. Between 1949 and 1953 the National Council of American Education (NCAE) published lists of "Red-ucators" - professors and other scientists who were publicly accused of associations with subversive, communist organizations. Event studies of publications and citations show that targeted scholars experienced a large and persistent decline in their research output. After the accusations, targeted scholars were 10% less likely to publish, and they published 25% fewer papers compared with other scholars in the same fields and at similar institutions. Scientists who were accused of multiple subversive affiliations suffered most. Notably, citations to existing work by targeted scholars declined only temporarily during the height of the movement and recovered as McCarthyism lost its force.
This paper investigates the career effects of mental health, focusing on depression, schizophrenia, and bipolar disorder (BD). Individual-level registry data from Denmark show that these disorders carry large earnings penalties, ranging from 34 percent for depression and 38 percent for BD to 74 percent for schizophrenia. To investigate the causal effects of mental health on a person’s career we exploit the approval of lithium as a maintenance treatment for BD in 1976. Baseline estimates compare career outcomes for people with and without access in their 20s, the typical age of onset for BD. These estimates show that access to treatment eliminates one third of the earnings penalty associated with BD and greatly reduces the risks of low or no earnings. Importantly, access to treatment reduces the risk of disability for a person with BD by more than half.
Focusing on bipolar disorder (BD), we investigate the link between mental health, creativity, and wealth. Analyzing population data for Denmark, we find that people with BD are more likely to be musicians, but less likely to hold other creative jobs than the population. Healthy siblings of people with BD, however, are consistently more likely to work in creative jobs. We also show people in the top decile of parental wealth are seven times as likely to work in creative professions compared with the bottom decile. Yet, wealth differences only explain a small portion of the link between BD and creativity.
Shell Shock: How Exposure to War-Time Combat Impacts Productivity
This paper investigates how trauma, due to exposure to war-time combat, affects productivity. Baseline estimates compare changes in successful patent filings from 1930 to 1970 for 24,822 draft-eligible American scientists who served in WWII with 27,981 draft-eligible scientists who did not serve. We use information on each scientist's military assignments and their service branches to measure variation in exposure to combat and match scientist with successful patent filings to measure changes in productivity following exposure. These analyses indicate severe and persistent adverse productivity effects of trauma: Compared with other draft-eligible scientists, scientists who saw combat experienced a significant decline in productivity for 10 years following the war. After 10 years, their productivity begins to recover slowly and incompletely. By comparison, scientists who served in administrative capacities within the same branch have no significant change in productivity, and scientists who served in research roles experienced a temporary increase in output. Only soldiers who served in the military corps suffered a decline in productivity that is comparable to the productivity changes for combatants. Compared with combatants, scientists who served in the medical corps took longer to begin their recovery, but unlike combatants they recovered fully. Ongoing research investigates the influence of selection into combat roles.
Demand uncertainties create major obstacles for financing technological innovation, as well as creativity in the arts. This paper uses detailed book-level data on Romantic Period English literature to investigate crowdfunding as a mechanism to finance innovation in the presence of demand uncertainties. A simple model yields conditions under which authors choose alternative financing, and specifically crowdfunding. We show that new authors, female authors, and authors in new genres face substantially greater demand uncertainty than established authors, men, and authors working in established genres.. Detailed book-level contract data reveal that entrants, women, and authors in new genres are more likely to crowdfund. We find that crowd-funded works have lower payoffs on average but are substantially more likely to become a major hit. Exploring variation across genres, we show that crowdfunded novels for women (and by women) were more likely to be published in multiple editions, suggesting that realized demand exceeded expected demand in this emerging genre. Crowdfunded women’s novels are also more likely to be translated and have an increased probability of long-run success. Using text analysis to measure novelty, we show that crowd-funded titles are likely to present new ideas than publisher-funded works.
Patents are intended to encourage innovation and economic growth. Yet, throughout history, countries have chosen piracy instead of patenting during their most critical phase of economic development. This book documents how the United States and European countries have used piracy in their early stages economic development to catch up to the technology frontier, and how they switched to patents once they reached the frontier.
Feeding the world’s growing population is one of the most critical policy challenges for the 21st century. With tightening constraints on natural resources, such as water and arable land, agricultural innovation is quickly becoming the most promising path meet the nutrient needs for future generations. Moreover, the increasing variability in the world’s climate intensifies the need for developing new crops that can tolerate extreme weather. Despite the urgency of this task, there is an active discussion on the returns to public and private spending in agricultural R&D. Since the 1990s, many of the world’s wealthier countries have scaled back their share of GDP devoted to agricultural R&D. Dwindling public support leaves universities, which, historically, have been a major source of agricultural innovation increasingly dependent on funding from industry, with uncertain effects on agricultural research. To help address these issues, this book provides new economic evidence on the sources of agricultural innovation, on challenges of measuring productivity, on the role of universities and their interactions with industry, and on emerging mechanisms to fund agricultural R&D.