short readsNov 15, 2019 Q&A: How Pew Research Center estimated the number of unauthorized immigrants in Europe 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.
short readsJul 12, 2019 Measuring illegal immigration: How Pew Research Center counts unauthorized immigrants in the U.S. 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.