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.
About Pew Research Center Pew Research Center is a nonpartisan fact tank that informs the public about the issues, attitudes and trends shaping the world. It conducts public opinion polling, demographic research, media content analysis and other empirical social science research. Pew Research Center does not take policy positions. It is a subsidiary of The Pew Charitable Trusts.