In 1921 and 1924, the United States first adopted nationality-based immigration quotas to stem the inflow of low-skilled Eastern and Southern Europeans (ESE) and preserve the “Nordic” character of its population. This paper investigates whether these quotas inadvertently discouraged ESE-born immigrant scientists. Hand-collected data on the birth place, year, immigration, education, and employment histories of more than 80,000 American scientists reveal a dramatic decline in the arrival of ESE-born immigrant scientists, with an estimated 33 missing ESE-born scientists per year. To examine how this decline affected US science and invention, we first 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 US scientists produced more than 60 percent fewer additional patents in response to the quotas. Equivalent analyses at the aggregate level of patenting, Indicate a 30 percent decline in US invention overall. This decline in invention persisted through World War II and into the 1960s.

Petra Moser is professor of Economics at NYU Stern and is visiting during this academic year 2019-20, the economics department at UC Berkeley. Her research combines methods from economic history and applied microeconomics to examine the determinants of creativity and innovation. She studies the behavior of inventors, composers, writers, and scientists from the 19th century to today to figure out what makes people creative, what encourages firms to take the risks that are inherent in innovation, and what types of institutions encourage people to do their best work. Her book project “Pirates and Patents” draws on records of 19th-century world fairs to examine how the US and Europe used piracy to catch up to the technology frontier.