The Immigration Policy Center has released a report called "Economic Progress via Legalization: Lessons from the Last Legalization Program" [1] which points out that the 1986 amnesty helped those amnestied improve their situations. However, there's little in their report that's remarkable and they don't take into account the balance between the benefits and costs of the amnesty; everything's always great when it comes to amnesty. On the one hand, those amnestied may have led to increased economic activity and that might have helped others. On the other hand, the cost to those others of competition for their jobs led to reduced wages. And, of course, all the other costs; see below.

Theirs is yet another in the long line of bogus economic studies designed to encourage comprehensive immigration reform. They don't take into account what would have happened if those amnestied had instead been encouraged to return home: the Mexican government and far-left racial power groups would have less power inside the U.S. than they do now, we'd have less illegal immigration (it's increased in part due to the network effect; Mexicans arriving here illegally know they have a support structure in place), and our own low-wage workers' wages would be higher. In fact, they as much as acknowledge the last (note that their report concentrates on what they call "IRCA immigrants", which they define as "Mexican immigrants of different age groups who came to the United States during the 1975 - 1981 period"):

But the fact remains that the data indicate that the IRCA population improved its status both as a group and compared to natives.

Good for them, not so good for the rest of us; we know which side the IPC is on.

The most "dramatic" change they offer is: "By 2006, only half as many IRCA immigrants were below the poverty line as in 1990." Meanwhile: "Use of public assistance among IRCA immigrants remained largely unchanged overall" We're also informed that the "home ownership rates [of IRCA immigrants] improved tremendously". Perhaps considering the mortgage meltdown the IPC should have kept that to themselves. In fact, little in the report presents amnesties as that beneficial to the U.S., and there are all those costs the IPC will never mention. If you want to throw the IPC for a loop, ask them to do similar reports on those from other countries, or ask them to give a full accounting of all the costs and benefits of amnesty.

[1] immigrationpolicy.org/special-reports/
economic-progress-legalization-lessons-last-legalization-program
Their credits: "This report was prepared for the Immigration Policy Center (IPC) of the American Immigration Council by Rob Paral and Associates, with writing by Rob Paral, Madura Wijewardena, and Walter Ewing of IPC."