Research also suggests that diversity and immigration have a net positive effect on productivity and economic prosperity. Immigration has also been associated with reductions in offshoring. A study by Harvard economist Nathan Nunn, Yale economist Nancy Qian and LSE economist Sandra Sequeira found that the Age of Mass Migration (1850–1920) contributed to "higher incomes, higher productivity, more innovation, and more industrialization" in the short-run and "higher incomes, less poverty, less unemployment, higher rates of urbanization, and greater educational attainment" in the long-run for the United States. Research also shows that migration to Latin America during the Age of Mass Migration had a positive impact on long-run economic development.