This week the National Venture Capital Association (NVCA) released "American Made: The Impact of Immigrant Entrepreneurs and Professionals on U.S. Competitiveness," a new study that reveals something that Silicon Valley netizens already know but scream for others to recognize: The immigration debate affects America's economy in a big way.

When most Americans think of immigration, illegal workers from Mexico usually spring to mind. In Brad Pitt's new movie "Babel," for instance, the housekeeper who endangers his character's kids is sent back to Mexico after being caught by border control.

Adding fuel to the fire, various politicians have hired illegal workers. Not all immigrants are illegal or a burden, however.

Vital to Economy
Indeed, apparently unknown to Hollywood and many in the political fray, a bunch of hardworking immigrants have been creating huge numbers of jobs and wealth for the very Americans that want to keep them out.

Immigrant-founded, venture-backed public companies today employ an estimated 220,000 people in the United States and more than 400,000 people globally, according to American Made. That's a lot of people -- and a lot of future voters who wouldn't be happy if they were unemployed.

The study also found that companies started by immigrants and initially backed by venture capital account for more than US$500 billion of total U.S. market capitalization. That's a lot of hard work and capital going toward making American lives better. Consider the immigrant influence on some of the companies everyone already knows.

PayPal was cofounded by Peter Thiel and Max Levchin, both of whom were born outside the United States. Google's (Nasdaq: GOOG) Sergey Brin, Yahoo's (Nasdaq: YHOO) Jerry Yang, and eBay's (Nasdaq: EBAY) Pierre Omidyar were immigrants too. In fact, it turns out that almost half -- 47 percent -- of America's current venture-backed companies have at least one immigrant founder. What if none of these people had come to the United States and instead had taken their ideas and skills elsewhere?

The answer is that the tech companies we know and love might have been created elsewhere, with all the benefits going to the people of the other country. Immigrants create jobs, wealth and economic growth. So why do their contributions seem to go unrecognized? Perhaps it is because it's easier for the news media to focus on problems.

Making It Difficult
Unmanned private spy planes on the border make for better headlines than Sun Microsystems' (Nasdaq: SUNW) immigrant founders, Vinod Khosla from India and Andreas von Bechtolsheim from Germany. This ignorance is not bliss, though, especially if it leads to poor policy decisions like cutting H-1B (work visa) quotas and making it tougher for skilled workers to enter the country.

More than two-thirds of survey respondents to the NVCA agreed that "U.S. immigration policy has made it more difficult than in the past to start a business in America," and "one-third of the respondents indicated that the lack of H-1B visas had influenced their firm's decision to place more personnel in facilities abroad."

The message entrepreneurs are collectively sending was summed up nicely by Sun Microsystems' cofounder Scott McNealy earlier this year. There are many talented people, he said, "who want to come here and live the American dream, and be part of the American economy. If they can't get in, they're still smart, and they are still going to set up shop somewhere else."

It would be stupid to let some other country take the planet's best and brightest so that they can compete with the United States. Indeed, one of the core strengths of America has been the willingness to accept others with open arms. That's not to say there are not talented people who were born here -- only that it is foolish to barricade ourselves from those who can help the country prosper.

The next time immigration comes up -- and it will, because Congress has not settled the issue -- policy makers and those who support them should look closer at the facts. There are many immigrants who create American jobs and wealth. U.S. policy should reflect that truth if Americans want to stay on top of the world's economic scene in the future.