This paper argues that the ability to keep innovations secret may be a key determinant of patenting. To test this hypothesis, the paper examines a newly-collected data set of more than 7,000 American and British innovations at four world's fairs between 1851 and 1915. Exhibition data show that...

Immigration quotas in the 1920s targeted “undesirable” nationalities to stem the inflow of low-skilled Eastern and Southern Europeans (ESE). Detailed biographical data for 91,638 American scientists reveal a dramatic decline in the arrival of ESE-born scientists after the quotas. Under the...

Historical accounts suggest that the arrival of German Jewish émigrés who fled the Nazi regime revolutionized U.S. science and innovation. This paper presents the first systematic analysis of the émigrés' effects on U.S. innovation. Difference-in-differences analyses compare changes in...

A growing empirical literature uses patent citations as a quality-adjusted measure for innovation, despite concerns about the validity of this measure. This paper links patents with objective measures of improvements in the quality of patented inventions – measured through performance in field...