SECRETARY WEINBERGER was arguing before the National Press Club the other day that cutting defense spending would mean lost jobs.

Defense jobs--because they generally involve highly skilled workers and large amounts of scarce raw materials--are among the most expensive jobs in the economy. The Defense Department estimates that the added $33 billion in defense outlays requested in the administration's budget would increase employment in defense-related industries by about 347,000 jobs. Each directly created job would thus cost almost $100,000.

The secretary's estimate of 350,000 jobs lost for each $10 billion cut from defense spending, however, takes account of the indirect effects of defense spending as it ripples out through the economy. This brings the average cost for each job down to about $30,000.

What's the matter with this estimate? Simply that it assumes that, if the money were not spent on defense, it would be buried in a hole or stashed away under someone's mattress. This, of course, wouldn't happen. The money would either be spent on other government functions, used to reduce the deficit or returned to taxpayers as a tax cut. Any one of these uses would produce more jobs than would defense spending.

For example, either a tax cut or spending on public works--such as highways and urban renewal-- would produce about 50 percent more jobs than the same amount of money spent on defense. Low-wage public service employment would create about three times as many jobs when all direct and indirect effects are taken into account.

There are reasons for increasing defense spending, but job creation isn't one of them.