But that actually understates the effect of illegal immigration on the state. As a percentage of population, Arizona has the highest concentration of illegal immigrants in the country. Based upon the Pew study, about 9 percent of Arizona's population consists of illegal immigrants.

Simply put, illegal immigration is, by far, the most influential demographic factor working on the state today. Yet, despite all the public clamor about it, the state is nowhere near thinking and acting sensibly about it.

Those who rail about the influence of illegal immigration are mostly focused on reducing the costs to taxpayers from it. The Federation for American Immigration Reform, which wants to sharply curtail immigration and provided most of the funding for Arizona's Proposition 200 last election, has estimated that illegal immigration is costing Arizona $1.3 billion a year.

But, for the most part, there's nothing the state, acting alone, can do about that.

FAIR totaled the cost associated with illegal immigration for education, emergency medical care and incarceration. Federal law requires the state to educate the children of illegal immigrants and provide emergency medical care. And the state certainly isn't going to let illegal immigrants who commit crimes go free to save some bucks.

Proposition 200 purported to deny illegal immigrants access to social services. But federal law already made them ineligible for the big-ticket items, such as Temporary Assistance for Needy Families (what most people think of as welfare) and Medicaid.

As interpreted by Attorney General Terry Goddard, Proposition 200 only expanded the general ban on social services for illegal immigrants to a few small-potatoes programs.

Some Proposition 200 proponents huffed and puffed about Goddard allegedly gutting the proposition. But a proposed legislative expansion this year still only hits small-potatoes programs, except for college education.

As a practical matter, the only way the cost of illegal immigration to Arizona taxpayers is going to be reduced is to reduce the flow of illegal immigration, and that requires federal action.

A fair review of American labor markets would indicate that the optimum number of Mexican immigrants would be somewhere between what is currently permitted legally and the combined legal and illegal immigration that is actually coming.

Making that happen, and making it stick, requires increasing legal immigration opportunities, difficult-to-forge identification for everyone, and enforced employer sanctions for hiring illegal immigrants.

The current populist cry of "protect the border first" simply delays actually reducing the flow of illegal immigration. There's no reason that border enforcement and fixing the pull of the American labor market cannot go hand-in-hand.

Back here in Arizona, the demographic influence of immigration, legal and illegal, needs to be a much bigger part of the public policy debate about other issues.

Immigration has a huge influence, for example, on the social welfare indicators on which Arizona supposedly lags behind. According to the Center for Immigration Studies, more than 40 percent of Arizona families living in poverty or without health insurance are, in fact, immigrant-led.

In other words, rather than regressing or not moving forward, many of those on the lower rungs of the economic ladder in Arizona have actually already substantially improved their standard of living over what it was in Mexico.

The effect of immigration also has to be a bigger part of the discussion of Arizona's economic performance. According to a study by the American Graduate School of International Management, Mexican immigrants make up 18 percent of the Arizona workforce, but receive only 8 percent of total payroll. So, there's a clear downward tug on the sort of averages some like to fret over.

To truly understand what's going on in Arizona, researchers have to begin looking at native and foreign-born populations individually.

Arizona is currently a place where a large number of Mexican immigrants can come to better their lives. That can be a good thing, particularly if it enhances or at least does not diminish the opportunities for the native-born.

But to manage and cope with the large effects of immigration in Arizona, we have to first better understand and measure them.



Reach Robb at robert.robb@arizonarepublic.com or (602) 444-8472. His column appears Sundays, Wednesdays and Fridays.