How Good are Proxies for Legal Status? Evidence from the Legalization of Two Million Mexicans

Two million Mexicans were granted lawful permanent residency in the U.S. under the Immigration Reform and Control Act of 1986 (IRCA). We find that a prominent proxy for legal status poorly detects this event. A decade after legalization, the share of Mexicans who are likely legal according to this proxy shows little change in survey data. Estimates rule out increases of three and eight percentage points relative to comparison groups of Mexican Americans and non-Hispanic Blacks, respectively – figures well below expectations based on administrative data. In contrast, an actual measure of status, citizenship, does rise in line with administrative facts.