The economic results of migration impact the economies of both the sending and receiving countries.
Economic impact on natives
According to David Card, Christian Dustmann, and Ian Preston, "most existing studies of the economic impacts of immigration suggest these impacts are small, and on average benefit the native population". In a survey of the existing literature, Örn B Bodvarsson and Hendrik Van den Berg write, "a comparison of the evidence from all the studies... makes it clear that, with very few exceptions, there is no strong statistical support for the view held by many members of the public, namely that immigration has an adverse effect on native-born workers in the destination country."
Studies show small but more mixed results (negative, positive or no impact), for low-skilled natives.
Research also suggests that cultural diversity has a net positive effect on the productivity of natives. A literature review of the economic impacts of immigration finds that the net fiscal impact of migrants varies across studies but that the most credible analyses typically find small and positive fiscal effects on average. According to the authors, "the net social impact of an immigrant over his or her lifetime depends substantially and in predictable ways on the immigrant's age at arrival, education, reason for migration, and similar". Studies of refugees' impact on native welfare are scant but the existing literature shows mixed results (negative, positive and no significant effects on native welfare).
Research on the economic effects of undocumented immigrants is even more scant but existing studies suggests that the effects are positive for the native population. A 2015 study shows that "increasing deportation rates and tightening border control weakens low-skilled labor markets, increasing unemployment of native low-skilled workers. Legalization, instead, decreases the unemployment rate of low-skilled natives and increases income per native."
United States
A survey of economists shows a consensus behind the view that high-skilled immigration makes the average American better off. A survey of the same economists also shows strong support behind the notion that low-skilled immigration makes the average American better off.
Overall immigration has not had much effect on native wage inequality but low-skill immigration has been linked to greater income inequality in the native population. According to labor economist Giovanni Peri, the existing literature suggests that there are no economic reasons why the American labor market could not easily absorb 100,000 Syrian refugees in a year.