https://techcrunch.com/2017/10/12/facebooks-ad-targeting-tools-could-be-a-valuable-supplement-to-census-data/

Official census forms are an invaluable source for demographic data throughout the country, but for trends that occur on the scale of weeks or months rather than years, they’re a bit lacking. But a new study shows that similar data used by Facebook to target ads could help fill in that blind spot.

Sociologist Emilio Zagheni at the University of Washington looked into the possibility, in this case specifically regarding migrants in the U.S. and their movements between states. He’s previously looked at this topici using Google+ and other internet-based metrics.