So what do we know about what happened to that earlier wave of immigrants? Only a little bit -- and hardly enough to measure the impact of a massive government policy change. The Department of Labor sponsored two survey studies following up on several thousand of the IRCA immigrants -- in 1989 and then again in 1992, five years after the law went into effect.
Those studies suggested that immigrants made significant wage gains in the years after legalization, many of them by obtaining better jobs. Government records also revealed over time how many of them became naturalized citizens. In 1996, the year the entire IRCA cohort was eligible, a quarter of a million were naturalized. By 2001, one-third of the entire group had been.
These naturalization rates suggest that many immigrants may not have been looking for citizenship so much as economic stability. That trend, too, is in keeping with what many immigrants say of their long-term intentions.
"When you talk to immigrants, many of them say that they plan in the long run to return home, to retire back to Mexico, to Central America," says Marc Rosenblum, the deputy director of the U.S. Immigration Program at the Migration Policy Institute. "They’re looking for short-term security."
Mexican immigrants under IRCA were also the least likely to seek citizenship, mirroring a long-term pattern. Being closer to home, Rosenblum suggests, may make it feel easier to go back. Until the late 1990s, Mexico also didn't offer dual citizenship.
Beyond the 1992 study, though, there is no survey data tracking how the following years unfolded. And there's similarly little known about the prospects over time of two smaller waves of immigrants granted reprieves -- in an effort to patch IRCA -- by Reagan and George H.W. Bush.
"That means that we don’t know a lot about some of the things like how their children have fared, their participation in the political process, other non-economic indicators of well-being and integration and health," Rosenblum says. "There’s a whole long list of things that we don’t really know, especially over time."
There's reason to suspect, however, that giving an immigrant legal status might impact much more than his or her job prospects. "There’s stress associated with the fear of deportation that would be reduced," Rosenblum says. And that implies that immigrants might have better health outcomes once that fear is removed — just as they'd have better outcomes thanks to access to health insurance that comes with better jobs.