Arizona has attacked illegal immigration with state laws that the US Federal Government says are unconstitutional because they preempt federal jurisdiction.

Rarely does one encounter actual data in this heated discussion, but detailed data are, indeed, being collected by the Mexican Migration Project at Princeton.  Douglas Massey, Director of the Office of Population Research at Princeton, quoted in the Apriul 25 Princeton Alumni Weekly, says that the popular impression of a flood of illegal immigrants is mistaken:

• The total number of illegal migrants from Mexico has changed little since the 1950’s in the U.S.
• Net illegal migration is now close to zero
• Because of tougher border enforcement (making reentry more difficult), more illegal migrants are now staying in the U.S.

The data are available, in SAS, SPSS and Stata formats, at http://mmp.opr.princeton.edu/

But wait….    Which Massey do you believe?

He was also quoted in the Washington Post April 24 saying the “massive boom in Mexican immigration is over” and an accompanying graph shows a doubling in immigration from Mexico from 1991 to 2000, then an 80% reduction from 2000 to 2010.  Clearly not a picture that has “changed little.”