Immigrant diversity, integration and worker productivity: uncovering the mechanisms behind ‘diversity spillover’ effects

A growing body of research is demonstrating a robust positive relationship between the diversity of a city’s foreign-born population in the USA and worker productivity. Other research has focused on diversity within firms, similarly finding positive effects in many cases. Although it appears that diverse teams within firms are better at problem-solving and are more creative, the exact mechanism(s) that drive the relationship between diversity and productivity at the scale of city-regions are less apparent and underexplored in extant research. Drawing on research from several fields, I describe four mechanisms that might drive the relationship between immigrant diversity and productivity at the urban level. I explore each mechanism with a pseudo panel of workers and fixed effects OLS regressions across U.S. Metropolitan Statistical Areas between 2011 and 2017. The results most strongly support that at the urban level, diversity enhances productivity through what I call ‘exposure effects’ and ‘interactive problem-solving’, wherein workers become more productive and more creative through exposure to new cultures and ways of thinking and through joint problem-solving. These results suggest that positive externalities arise when coupling rising immigrant diversity with the social integration of people from diverse backgrounds.