The diffusion and use of new ideas is critical for producing innovations and realizing their potential. We explore how characteristics of innovators and potential adopters affect the adoption of important, new scientific ideas in networks. Using rich data on biomedical researchers and their networks, natural language processing, and a novel two-way fixed effects strategy, we find that new ideas introduced by female scientists are underutilized for two reasons. First, female innovators are less connected than men. Second, at short network distances, researchers (especially men) adopt women’s ideas less. Similar gaps hold for underrepresented racial and ethnic minorities.

By examining the ethnic identity of authors in over 2.5 million scientific papers written by US-based authors from 1985 to 2008, we find that persons of similar ethnicity coauthor together more frequently than predicted by their proportion among authors. The greater homophily is associated with publication in lower-impact journals and with fewer citations. Meanwhile, papers with authors in more locations and with longer reference lists get published in higher-impact journals and receive more citations. These findings suggest that diversity in inputs by author ethnicity, location, and references leads to greater contributions to science as measured by impact factors and citations.

We study how a significant relaxation of internal migration restrictions affects labor market outcomes of incumbent migrants and natives, exploiting the 2014 hukou reform in China, which substantially removed the migration barriers of cities with an urban population below 5 million (nonmegacities). Using a difference-in-differences method, we find that migrants’ wages in nonmegacities experienced approximately a 2.6%–7.9% decline relative to that in megacities after the policy. The policy had nonnegative impacts on the wages of natives in nonmegacities. These results suggest that the downward wage pressure imposed by new migrants falls primarily on incumbent migrants rather than on natives.