“…The U.S. Census Bureau always needs to have good population estimates, and you need to know how many illegal immigrants there are to refine those estimates,” she says. But since the census doesn’t ask if someone’s an illegal immigrant, getting a count is “tricky,” she adds.

The census does ask for place of birth, duration of residence in the United States and whether the person is a U.S. citizen, “so we have a pretty fair sense of the size of the foreign-born population,” explains Van Hook, who earned a Ph.D. in sociology from the University of Texas in 1996 and has been at BGSU since 1999.

Administrative records—of births, deaths and naturalizations, for example—are used to develop estimates of the legally resident foreign-born population, which in 2000 numbered roughly 23.6 million. At the same time, the 2000 census indicated about 31 million foreign-born people were in the United States, leaving a difference that can be assumed is illegal immigrants—but with assumptions, she points out.

HERE

For instance, because foreign-born legal residents leave the country, too, an emigration estimate is built into the legal-resident count. The problem, however, is that the government stopped keeping actual records of “outmigration” of the legally resident foreign-born in the 1950s, so that factor may not be accurately estimated, according to Van Hook…”

AJC: Your reporters shouldn’t require more than a week or two to figure this out.