linguistic:paraphrasing, quality:corruption
Impact on immigrants

Research on a migration lottery allowing Tongans to move to New Zealand found that the lottery winners saw a 263% increase in income from migrating (after only one year in New Zealand) relative to the unsuccessful lottery entrants. A longer-term study on the Tongan lottery winners finds that they "continue to earn almost 300 percent more than non-migrants, have better mental health, live in households with more than 250 percent higher expenditure, own more vehicles, and have more durable assets". A conservative estimate of their lifetime gain to migration is NZ$315,000 in net present value terms (approximately US$237,000).

A 2017 study of Mexican immigrant households in the United States found that by virtue of moving to the United States, the households increase their incomes more than fivefold immediately. The study also found that the "average gains accruing to migrants surpass those of even the most successful current programs of economic development."

A 2017 study of European migrant workers in the UK shows that upon accession to the EU, the migrant workers see a substantial positive impact on their earnings. The data indicate that acquiring EU status raises earnings for the workers by giving them the right to freely change jobs.

A 2017 study in the Quarterly Journal of Economics found that immigrants from middle- and low-income countries to the United States increased their wages by a factor of two to three upon migration.