"Industry officials say with confidence that 7.3 million jobs will disappear if the Obama administration goes through with tighter rules to reduce smog. The industry-sponsored researcher who came up with that number isn't so sure.

'There's uncertainty around that,' economist Don Norman said of the 'shockingly high' job loss number he extrapolated using a study sponsored by the oil and natural gas industry's American Petroleum Institute and covering just 11 states.

'Even if the numbers are half of that, the number is huge,' he said.

Norman, like most economists on any side of any issue, is quick to acknowledge that economic models used for calculating estimates of job losses and other effects from a particular policy depend on the assumptions fed into them, and that the reality can be far different.

Yet in testimony before House committees now run by anti-regulation Republicans, industry witnesses repeat numbers from imprecise economic models. Members of Congress often cite the same figures without the researchers' caveats. "

Larry Margasak reports for the Associated Press February 28, 2011. [2]