Unauthorized Immigration

54% of Hispanics in the U.S. say establishing a way for most unauthorized immigrants to stay in the country legally is very important.

Every year, we publish hundreds of reports, blog posts, digital essays and other studies. Here are some of our most noteworthy findings from the past year.

In this Q&A and video, learn about the methods and data sources the Center used to estimate the number of unauthorized immigrants in Europe.

The number of unauthorized immigrants living in Europe increased between 2014 and 2016, then leveled off to an estimated 3.9 million to 4.8 million in 2017, according to new estimates from Pew Research Center.

The size of Europe’s unauthorized immigrant population in 2017 was less than half the number in the United States.

Most live in Germany, the UK, Italy and France, and about half had arrived in Europe in recent years. Overall, these migrants account for less than 1% of Europe’s total population.

The first full fiscal year of the Trump administration saw large increases in the number of people arrested and criminally prosecuted for immigration offenses.

Most continue to favor legal status for undocumented immigrants

Jeffrey S. Passel, senior demographer, on the research techniques used to derive the unauthorized immigrant population estimate in the U.S. and the challenges involved.

While Mexico is the United States' largest source of immigrants, the number of Mexican immigrants living in the U.S. illegally has declined since 2007.