According to the Bureau of Laobr Statistics, as of March 2009 there were 2.7 million job openings in the United States. This is down 1.4 million job openings in the last year.
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Given that unemployment has severly spiked in the last year + that means there are many more people fighting for far fewer jobs. Companies just don't want to take the risk and expand their work force---and I'm guessing that with the big supply of workers looking for employment, companies that are hiring could likely afford to pay less in wages/benefits than what they were doling out a mere 2 years ago.