I'm confused about immigration.

We libertarians believe in free trade. That includes trade in labor, too. New people bring us not just labor, but also good new ideas.

Open immigration during America's first hundred years helped make America rich.

Open immigration is dangerous today, however, because some immigrants want to murder us. And now that America is a welfare state, some want to come here just to freeload.

That great champion of freedom economist Milton Friedman said Mexican immigration is a good thing -- but only so long as it's illegal. "Why? Because as long as it's illegal for people to come, they don't qualify for welfare and Social Security. So they migrate to jobs."

But closing our eyes to illegal immigration cannot be good policy. So what should Americans do?

I sat down with Heather MacDonald of the conservative Manhattan Institute, author of "The Immigration Solution," and Jason Riley of The Wall Street Journal's editorial board, author of "Let Them In." I respect them both. But they radically disagree on immigration policy.

"The case for open borders is a case for letting the law of supply and demand, the free market, determine the level of immigration," Riley said. "Right now, that determination is being made by politicians and public policy makers. ... And like all exercises in Soviet-style central planning, it's been a complete disaster. We have thriving markets in document fraud ... and 12 million-plus illegal aliens. ... (W)e would do better to move to a system that allowed the free market to determine the level of immigration. And that's the case for open borders." Riley proposes a guest-worker program. "That is the way to reduce illegal immigration."

Heather MacDonald retorts:

"A country is not a firm. And it is absolutely the prerogative of a nation and its people to decide its immigration policy. ... We should have an immigration policy that accentuates our natural economic advantage in the 21st century, which is as a high-tech, high-science economy. ... (T)he overwhelming number of immigrants that are coming in -- largely illegally -- are extremely low skilled."

MacDonald worries that "we're facing, for the first time in this country's history ... the first decrease in national literacy and numeracy ... . "

She wants to copy Australia's and Canada's policy: "high skills, English language and education....We should be looking out for our own economic self-interest." Riley disagreed with MacDonald's claim that Mexican immigrants don't fit America's modern economy.

"(T)oday's immigrants coming here are not different in terms of their behavior patterns, in terms of their assimilation levels. They are simply newer."

"Immigrants increase crime!" is another charge hurled at illegals, but the data don't bear that out. There has been a surge in immigration over recent years, but crime has been dropping. Crime has dropped in the border areas of Arizona and California, too.

MacDonald said crime was high during immigration surges in the 1970s and '80s, and attributed the recent drop to higher incarceration rates. But Riley noted:

"Incarceration reports from the Justice Department ... show that the native-born are five times more likely than the immigrant population to be arrested and incarcerated ..."

But if today's illegals are not eligible for welfare, less likely to commit crimes and eager to work, why are people in the border states so ticked off?

"Why wouldn't they be?" Riley said. "It's chaos down there. There's trespassing. There are people breaking the law. We're a nation of laws. It's out of control. The question is how to fix it. And I don't think sealing off the border is the best way to fix it. I think regulating the flow is the best way to fix it."

It would be easier to "regulate the flow" if America made it easier for people to work here legally. State Department data show that a British Ph.D. in bioengineering must wait about six months to get a Green Card. A South African computer programmer, six years. An Indian computer programmer, 35 years.

A Mexican with a high school diploma must wait a theoretical 131 years! No wonder people sneak into America.

Black markets make problems worse. America should let more people come here legally.

John Stossel is host of "Stossel" on the Fox Business Network. He's the author of "Give Me a Break" and of "Myth, Lies, and Downright Stupidity." To find out more about John Stossel, visit his site at johnstossel.com. To read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate Web page at www.creators.com.

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