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.
This paper uses rich biographical data for 50,000 American scientists, linked with publications, to investigate how children affect women in science. First, we document that mothers have a unique lifecycle pattern of productivity: Publications by mothers decline in their mid 30s, stay low for roughly seven years, and then recover in their late 30s and early 40s. This transient decline is unique to mothers; publications by other scientists peak around their mid 30s. Event studies show that children reduce the productivity of mothers but not fathers; these effects are especially strong when children are young, below school age. The effects of children are especially large and persistent for women who are married to another scientist. Fathers in academic couples become more productive after the birth of their first child while the productivity of mothers declines permanently. Gender differences in the impact of children have important implications for promotions. Just 27% of female assistant professors with children get tenure, compared with 48% of fathers and 46% of other women. Women internalize these costs by getting more education, marrying late, and having fewer children or not having children at all. Examining selection, we find that mothers who survive in science are extremely positively selected.
How does childhood socioeconomic status (SES) influence a person's chances to participate and succeed in science? We investigate this question by using machine-learning methods to link scientists in a comprehensive biographical directory, the American Men of Science (1921), with individual census records and publications. Examining participation, we find that children from low-SES families are underrepresented in science. Investigating inequality beyond participation, we show that, even conditional on becoming a scientist, SES matters for peer recognition in science. Scientists from high-SES families have 38% higher odds of becoming stars, controlling for publications and citations. Using the text that describes the research of each scientist to assign scientists to disciplines, we examine differences across disciplines. These analyses reveal that mathematics is the only discipline in which the influence of SES operates through publications. Controlling for elite undergraduate or graduate degrees, high-SES scientists have 34% and 36% higher odds of becoming stars. Controls for birth order, family size, or foreign-born parents leave the estimates unchanged, emphasizing the importance of childhood SES.
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.
We examine how exposure to combat affected American scientists after WWII. To construct the data for this analysis, we use natural language processing to match 84,556 American scientists with 9 million enlistment records and hospital admissions cards. To address selection into enlistment and combat, we create a propensity-matched control group of non-enlisted, draft-eligible scientists of similar age, education, occupation, and marital status. Event studies that compare changes in publishing for enlisted and non-enlisted, draft-eligible scientists show that the enlisted were 18% less likely to publish 5-6 years after the end of their military service. To investigate the effects of exposure to combat on enlisted scientists, we estimate event studies comparing scientists in combat roles with other enlisted scientists. These analysis reveal a large and persistent additional decline in publishing: 9-10 years after enlistment, scientists who had served in combat were 69% less likely to publish compared with other enlisted scientists. Data from hospital admissions records indicate that this persistent decline cannot be explained by physical wounds.
This paper uses the approval of lithium as a maintenance treatment for bipolar disorder (BD) to investigate the career effects of mental health. Focusing on Denmark, where lithium was approved in 1976, we isolate the effects of access to treatment innovations by comparing labor market outcomes for people 1) with and without BD, 2) between cohorts who had access at age 20 (a typical age of onset for BD) and older cohorts, and 3) relative to people with other mental conditions, to control for forces that changed the career effects of mental health disorders over time. To control for the influence of a person’s family background, all specifications include family fixed effects. Using registry data on earnings and diagnoses, we find that access to treatment innovations increases labor market participation by 30 percent and earnings by 26 percent. The benefits of treatment operate largely through a reduction in the risk of disability, rather than through changes in occupational sorting or educational achievement. Benefits are similar for men and women, but larger for people with less parental wealth.
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.
How does public funding affect creative output in the arts? To answer this question, we exploit exogenous variation in exposure to public funding cuts due to Italy’s unification in 1861. Using theater-level performance data as a measure of creativity, we find that theaters more exposed to cuts put on fewer shows, produced fewer new works, and shifted towards more popular forms of entertainment. The impact of cuts was more severe in areas with low income and smaller cities. In the long run, theaters more exposed to funding cuts were more likely to close or be replaced by movie theaters.
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.
“Did Plant Patents Create the American Rose?” (with Paul Rhode) in Joshua Lerner and Scott Stern (eds). The Rate and Direction of Technological Change, Chicago University of Chicago Press, 2012, pp. 413-41.