A new study out this week by the Manhattan Institute should dispel a few myths on immigrant assimilation. The study looked at a range of factors -- economic, cultural, and civic -- to assess whether today's immigrants are becoming part of the American mainstream. But it also compared this generation of immigrants to the Great Wave who came to America's shores in the early part of the 20th century. The good news is that today's immigrants appear to be assimilating at faster rates than those older generations of immigrants, even though they start out with more disadvantages.

Not surprisingly, some immigrant groups -- Canadians, Cubans, and Filipinos -- are perfectly assimilated on economic measures, while others, especially Mexicans, lag behind. The study's author, Duke University professor Jacob L. Vigdor, looked at earned income, labor force participation, unemployment, occupation, educational attainment, and home ownership in computing economic assimilation. On these measures Canadian, Cuban, and Filipino immigrants were indistinguishable from the native-born.

But the study also contained some interesting surprises. For example, even though Vietnamese immigrants scored 99 (on a scale of 100) on economic assimilation and exhibited the highest degree of civic assimilation (as measured by naturalization rates and military service), they scored about the same on cultural assimilation (as measured by English proficiency, intermarriage, and childbearing) as Mexicans and Salvadorans. And the groups that fared the worst on cultural assimilation measures were Indians and Chinese; while Mexicans, Salvadorans, Canadians, and Indians measured poorly on civic assimilation.

The study did not distinguish between immigrants who entered the country legally and those who entered illegally, because census data don't include such information. But, of course, across all measures, legal status is critical to assimilation. Mexicans are far more likely than other immigrants to have entered the U.S. illegally, so it's little wonder they have the lowest civic assimilation rates and fare more poorly on economic measures.

But, what about Canadian and Indian immigrants? There's little clue why they don't join the military or become citizens at higher rates, but Prof. Vigdor does suggest that those who scored highest on civic assimilation, Vietnamese and Filipinos, come from countries that experienced recent U.S. military intervention in the past 100 years; but then so did the Dominican Republic, whose immigrants score in the middle range on civic assimilation.

The immigration debate -- at least at the national level -- has simmered down since its boiling point last summer. Congress continues to abrogate its responsibility to come up with reasonable immigration reform, but it can't avoid doing so forever. States and local jurisdictions have already tried to fill the void, but with mixed -- you might say schizophrenic -- results. Arizona, for example, passed tough laws to punish employers who hire illegal immigrants, only to find itself in a labor crunch, with dire consequences for the state economy. Now Arizona, Colorado, and a handful of other states are exploring whether they can create their own "guest worker" programs to bring in more Mexican workers.

When Congress does get around to changing our immigration laws, it should consider ways of encouraging the assimilation of immigrants, as well deciding on whom and how many to admit. We should give priority to immigrants who already speak English, since this is a key factor in their successful integration into American society. That doesn't mean we take only people who hail from English-speaking countries; language is, after all, a skill that can be learned. But why not give incentives for those wanting to come here to learn English before they get their green card? And why not encourage employers who want to hire these workers by giving them tax incentives if they offer on-the-job English classes to improve immigrants' skills? We could also give priority admission to immigrants willing to serve in the U.S. military, provided they have the requisite English and educational skills necessary.

Successful assimilation should be the goal of U.S. immigration policy. Instead, it's usually given short shrift in drafting immigration laws. When Congress takes up the issue again, as it most assuredly must next year, we should look to improving our assimilation index across all measures: economic, cultural, and civic.