Undocumented immigration, in particular, has waned because of the recession and beefed-up border security.

As an unintended consequence, immigrant families have tended to settle in the United States rather than periodically return to their native countries, as they did in the past. Because these households include proportionately more women of childbearing age, future Hispanic population growth will come from their children and grandchildren.

These U.S.-born Hispanics will make up a quarter of labor-force growth in the next two decades, according to demographer Jeffrey Passel of the Pew Hispanic Center. Their level of educational achievement will be crucial to their economic success in an increasingly information-based economy.

The recent research shows children of immigrants will more likely attain them if their unauthorized parents are given an opportunity to legalize their status.

Researchers at the University of California Irvine and the University of California Los Angeles surveyed adult children (ages 20 to 40) of Asian and Hispanic immigrants living in Los Angeles. Because Mexicans constituted the vast majority of immigrants, legal and undocumented, in the country during the 1980s, the 2006 survey — known as Immigration and Intergenerational Mobility in Metropolitan Los Angeles — focused on the experiences of their offspring.

Adult children whose immigrant parents entered the United States legally or took a pathway to citizenship under the 1986 Act spoke English better and in more settings, more likely completed high school and graduated from college and landed higher-paying jobs than those whose fathers remained unauthorized.

Specifically, the offspring of unauthorized fathers who were legalized or became citizens were 25 percent less likely to drop out of high school and 70 percent more likely to earn a college degree. And they earned 30 percent more money than those whose fathers lacked legal status.

Research done on the Mexican-origin middle class in this country also shows the legalization opportunities in the 1986 Act translated into future educational and economic benefits. As in the L.A. survey, the now-middle-class offspring of legalized parents tended to be better educated and hold higher-paying jobs — to be more solidly middle class — than the adult children of parents unable to legalize their status.

This research strongly suggests the benefits of comprehensive immigration reform today would extend to the next generation and beyond.

We’re not talking small numbers here. Nearly half the country’s unauthorized households are couples with children, and in about 75 percent of them, the children are U.S. citizens, according to the Pew Hispanic Center.

Allowing 4 million children — the Pew estimate for 2008 — to live in the twilight world of an undocumented household represents an enormous waste of human potential. These children — whose undocumented parents are more vulnerable to exploitative working conditions, earn far less money and are ever-fearful of being found out — are less likely to encounter the educational and job opportunities that could improve their situations.

This is potentially bad news for the U.S. economy. The most educated generation in history, the baby boomers, will begin retiring next year. Roughly 1.4 million jobs could open up annually in the top half of the labor market, the sociologist Richard Alba estimates, with whites filling two-thirds of them.

For the economy to keep growing, a significant proportion of the skilled jobs left vacant by retiring boomers will need to be filled by minorities. But if a sizable chunk of the future labor force is under- or unprepared to do so because their parents’ undocumented status stunted their educational development, who’s going to replace the baby boomers?

Time is not on our side. President Barack Obama’s deployment of 1,200 National Guard troops to the border and call for $500 million for tougher border enforcement plays into the current anti-immigrant political climate that hinders the educational and economic assimilation of immigrants and their U.S.-born children. The expected Republican gains in the midterms will very likely push comprehensive reform further down the road.

By not working toward an overhaul of our immigration laws that includes a path to citizenship, we may end up committing economic suicide in the name of politics.

Jody Agius Vallejo, an assistant sociology professor at the University of Southern California, is writing a book on the Mexican-origin middle class in the United States.