linguistic:translation, structural:expansion
Impact on the sending countries

Research suggests that migration is beneficial both to the receiving and sending countries. According to one study, welfare increases in both types of countries: "welfare impact of observed levels of migration is substantial, at about 5% to 10% for the main receiving countries and about 10% in countries with large incoming remittances". A study of equivalent workers in the United States and 42 developing countries found that "median wage gap for a male, unskilled (9 years of schooling), 35-year-old, urban formal sector worker born and educated in a developing country is P$15,400 per year at purchasing power parity". A 2014 survey of the existing literature on emigration finds that a 10 percent emigrant supply shock would increase wages in the sending country by 2–5.5%.

Remittances increase living standards in the country of origin. Remittances are a large share of the GDP of many developing countries. A study on remittances to Mexico found that remittances lead to a substantial increase in the availability of public services in Mexico, surpassing government spending in some localities.

Research finds that emigration and low migration barriers has net positive effects on human capital formation in the sending countries. This means that there is a "brain gain" instead of a " brain drain " to emigration. Emigration has also been linked to innovation in cases where the migrants return to their home country after developing skills abroad.

One study finds that sending countries benefit indirectly in the long-run on the emigration of skilled workers because those skilled workers are able to innovate more in developed countries, which the sending countries are able to benefit on as a positive externality. Greater emigration of skilled workers consequently leads to greater economic growth and welfare improvements in the long-run. The negative effects of high-skill emigration remain largely unfounded. According to economist Michael Clemens, it has not been shown that restrictions on high-skill emigration reduce shortages in the countries of origin.

Research also suggests that emigration, remittances and return migration can have a positive impact on political institutions and democratization in the country of origin. According to Abel Escribà-Folch, Joseph Wright, and Covadonga Meseguer, remittances "provide resources that make political opposition possible, and they decrease government dependency, undermining the patronage strategies underpinning authoritarianism." Research also shows that remittances can lower the risk of civil war in the country of origin.

Research suggests that emigration causes an increase in the wages of those who remain in the country of origin. A 2014 survey of the existing literature on emigration finds that a 10 percent emigrant supply shock would increase wages in the sending country by 2–5.5%. A study of emigration from Poland shows that it led to a slight increase in wages for high- and medium-skilled workers for remaining Poles. A 2013 study finds that emigration from Eastern Europe after the 2004 EU enlargement increased the wages of remaining young workers in the country of origin by 6%, while it had no effect on the wages of old workers. The wages of Lithuanian men increased as a result of post-EU enlargement emigration. Return migration is associated with greater household firm revenues. Emigration leads to boosts in foreign direct investment to their home country.

Some research shows that the remittance effect is not strong enough to make the remaining natives in countries with high emigration flows better off.