Looks like federal agencies are making it harder for companies to get temporary visas for foreign workers.  And it's creating a burden for firms that can't run their businesses without such employees.

Industries that depend on seasonal workers, agricultural laborers, and professionals such as computer programmers are having a particularly bad time. According to BloombergBusinessweek, for example, H-2B visas for seasonal workers decreased 52 percent last year. And a recent report by the ombudsman at the US Citizenship & Immigration Service found that agency requests for more evidence from companies seeking H1-B visas for programmers and other professional jobs almost doubled in 2009.

The crackdown also is especially onerous for many small businesses, because they lack the resources to manage visa applications that larger companies have.

Why is this happening now? The moves come, at least in part, because of fears that "foreign nationals are taking the place of US workers," according to Robert Groban, an immigration lawyer in New York quoted in the story. But it's a fear that's probably not grounded in reality. For one thing, even in a down economy businesses that use seasonal or agricultural workers say they  can't find enough US citizens to do the work, either because they're hiring for jobs most Americans don't want or they can't afford to pay wages that would attract more US workers. The situation for companies that need people with technical skills is less clear, although the real issue probably also is an unwillingness or inability to pay higher wages.

What's more according to a recent paper from the San Francisco Federal Reserve, "There is no evidence that immigrants crowd out US-born workers in either the short or long run." Giovanni Peri, an associate professor at the University of California-Davis and a visiting scholar at the Fed, concludes that immigrants not only tend to take jobs that US workers avoid, but also contribute to overall productivity.  "On net, immigrants expand the US economy's productive capacity, stimulate investment, and promote specialization that in the long run boosts productivity,"he writes.

Certainly with an unemployment rate near 10 percent, it's in the government's interest to encourage US companies to hire US workers. But cracking down on employment visas hurts not only businesses that traditionally have depended on such workers, but the economy as a whole.