In any downturn that doesn't last for years, infrastructure spending suffers from a basic problem: By the time money is actually spent on construction, the recession has passed. "Practically speaking, public works involve long start-up lags," the Congressional Budget Office wrote in a study earlier this year. "Large-scale construction projects of any type require years of planning and preparation. Even those that are 'on the shelf' generally cannot be undertaken quickly enough to provide timely stimulus to the economy."

This common-sense objection to the stimulative powers of infrastructure spending has been made even by Obama advisers. One of Obama's chief economic advisers, Jason Furman, wrote with former Clinton aide Douglas Elmendorf in January, "In the past, infrastructure projects that were initiated as the economy started to weaken did not involve substantial amounts of spending until after the economy had recovered." Another Obama economic adviser, Alan Blinder, noted "the lengthy time lags" in infrastructure projects in a 2004 paper and argued that "accelerating the pace of spending on public works for [economic] stabilization purposes would be inefficient and wasteful."

Infrastructure spending is proffered as a means to stimulate our way out of a potential deflation of the sort that gripped Japan after its stock and real estate bubbles burst in the 1990s. But the Japanese passed stimulus package after stimulus package, including billions of dollars for infrastructure, to no avail. They paved anything that stood still. In a project only Ted Stevens could love, they spent $7 billion on a bridge between two islands, even though the ferry service between them was barely used.

The spending failed because it went to wasteful projects favored by politicians for parochial reasons. The Japanese also made the mistake of raising taxes in 1997 to pay for all the spending, depressing the economy again. It makes you wonder: What U.S. political leader has been promising more public-works spending - to be allocated by a pork-happy Congress - funded by tax increases? (Hint: See the guy with the cigarette holder on the cover of Time.)

The cliché of the hour is that we suffer from "crumbling" infrastructure. There is truth to it. Miles traveled nearly doubled from 1980 to 2005, and the transportation network hasn't kept up. But if investment in infrastructure isn't applied intelligently - more intelligently than it's possible to imagine in the current panic - it will only fund a make-work program to create concrete monuments to pork-barreling congressmen. "Infrastructure should be seen," writes Sam Staley, co-author of the new book "Mobility First," "as a way to boost the speed of information and movement of goods, not as a quickie jobs program."