Paul Krugman on some of the Republican arguments against Obama’s stimulus package.

But the obvious cheap shots don’t pose as much danger to the Obama administration’s efforts to get a plan through as arguments and assertions that are equally fraudulent but can seem superficially plausible to those who don’t know their way around economic concepts and numbers. So as a public service, let me try to debunk some of the major antistimulus arguments that have already surfaced. Any time you hear someone reciting one of these arguments, write him or her off as a dishonest flack.

First, there’s the bogus talking point that the Obama plan will cost $275,000 per job created. Why is it bogus? Because it involves taking the cost of a plan that will extend over several years, creating millions of jobs each year, and dividing it by the jobs created in just one of those years.

It’s as if an opponent of the school lunch program were to take an estimate of the cost of that program over the next five years, then divide it by the number of lunches provided in just one of those years, and assert that the program was hugely wasteful, because it cost $13 per lunch. (The actual cost of a free school lunch, by the way, is $2.57.)

The true cost per job of the Obama plan will probably be closer to $100,000 than $275,000 — and the net cost will be as little as $60,000 once you take into account the fact that a stronger economy means higher tax receipts.

Next, write off anyone who asserts that it’s always better to cut taxes than to increase government spending because taxpayers, not bureaucrats, are the best judges of how to spend their money.

Here’s how to think about this argument: it implies that we should shut down the air traffic control system. After all, that system is paid for with fees on air tickets — and surely it would be better to let the flying public keep its money rather than hand it over to government bureaucrats. If that would mean lots of midair collisions, hey, stuff happens.