Studies of Immigrant Success Skewed?

UPI reported that: Descendants of Mexican immigrants in the United States may be making better socioeconomic progress than many studies indicate, researchers say. Some recent studies have raised red flags about the economic progress of Mexican-Americans, saying third- and fourth-generation Mexican-Americans are no more likely to graduate high school than second-generation Mexican-Americans, with wages stagnating after the second generation as well. However, two U.S. economists, writing in The Journal of Labor Economics, say these studies all share a common problem that is skewing the results. "Almost without exception, studies of later-generation Mexican-Americans rely on ethnic self-identification to identify the population of interest," Brian Duncan of the University of Colorado and Stephen Trejo of the University of Texas said. That's a problem in the studies, the researchers say, because many immigrant descendants may not identify themselves as Mexican-American on surveys or census forms.