Bryan Caplan of George Mason University posted some comments I sent him along with some questions about a recent blog post of his. His questions are in quotes, my responses follow. First, some background.
It’s important to separate immigration (permanent) from migration (temporary). Much of what we think of as “immigration” is actually migration as many of them return home. Dudley Baines (page 35) summarizes some estimates of return migration from America’s past.
Country/Region of Origin Return Rates
English & Welsh 40%
Austro-Hungarians & Poles 30-40%
Gould estimates a 60 percent return rate for Italians – similar to Mexican unauthorized immigrants from 1965-1985.
There were three parts to the Immigration Reform and Control Act of 1986 that all affected both immigration and migration. The first part was the amnesty. The second was employer sanctions through the I-9 form that was supposed to turn off the jobs magnet. The third was increased border security to keep them out. For the first two questions, I assume the rest of IRCA was passed.