Patenting in the United States rose 31 percent after 1933 in the fields the émigré chemists were working in...
Whether and how high-skill immigrants affect productivity and innovation in their adopted country is a subject of long-running debate. In German-Jewish Émigrés and U.S. Invention (NBER Working Paper No. 19962), Petra Moser, Alessandra Voena, and Fabian Waldinger find that the German Jewish chemists who fled Nazi Germany and Austria dramatically boosted America's scientific prowess. Patenting in the United States rose 31 percent after 1933 in the fields the émigré chemists were working in, and it stayed at elevated levels into the 1950s.
Some historical accounts credit the émigrés of the 1930s with revolutionizing American science in fields such as physics, where several formed the core of the Manhattan Project, and chemistry, where three won Nobel Prizes. However, other accounts are less positive and suggest that the Jewish émigrés met with anti-Semitism in the United States and found it difficult to find jobs. By systematically evaluating the effect of émigrés in chemistry, a field in which innovations are routinely patented and are consequently easy to measure, this study offers the first empirical analysis of their impact. The baseline estimate may underestimate the émigrés' total impact because those who moved to the United States may have been less productive than other chemists who had the opportunity to stay in Europe at prestigious British universities, and because some émigrés may not have been able to find work in the most attractive and productive U.S. research fields, leading to underutilization of their talents.
One of the study's most striking findings is that the arrival of highly skilled émigrés appears to have encouraged American inventors to patent more in the research fields in which the émigrés were active. This was not the result of rising productivity of U.S. scientists who had already been active inventors in these research fields. There was no significant change in the number of patents that existing inventors produced in the fields of star émigré scientists. Rather, the increase is attributable to a shift in the fields of specialization of new scientists. Prior to the arrival of the émigrés in 1933, U.S. researchers were less inclined to enter the sub-fields of chemistry studied by the émigrés than to enter other fields. In later years, this pattern reversed. Moreover, the new researchers who began patenting in the fields of the émigrés were primarily scientists who had never patented before. The authors conclude that "the émigrés' effect on U.S. patenting was driven primarily by their ability to attract a new group of domestic inventors to their fields." The younger U.S. scientists who were trained by the star émigré professors in turn trained other researchers in the methods they had learned. The paper notes that "U.S. inventors who collaborated with émigré professors began to patent at substantially higher levels in the 1940s and continued to be exceptionally productive in the 1950s."
-- Laurent Belsie