American cities should stop the convention center space race. Public spending for convention centers has doubled over the past decade, to almost $2.5 billion a year. Exhibit space has increased 50% since 1990, to 61 million square feet in 2003. And 44 cities have plans for expansion or new centers in the hopes of increasing jobs, tourism, and tax revenue.

The fact is, the convention business is shrinking, and was doing so well before September 11. Convention centers are now expensive, money-losing propositions, even before you count the costs and debt.

These are the conclusions of a professor in the Department of Public Administration at the University of Texas at San Antonio, Heywood Sanders, who has spent almost a quarter century studying convention centers and their economic impact.

Mr. Sanders makes his case in a 35-page research brief for the Brookings Institution, released this week, called “Space Available: The Realities of Convention Centers as Economic Development Strategy.”

If you are a city official, editorial writer, or taxpayer, you should read this report.

Wall Street won’t want you to, of course. Wall Street makes millions of dollars underwriting bonds for convention centers and convention center hotels, and doesn’t want states and localities to stop betting on the future success of the convention business.

“The problem, quite simply, boils down to this: Demand for convention space is not keeping pace with its growing supply, severely limiting the ability of individual centers to accrue hoped-for economic benefits, and ultimately calling into question the value of these large public investments,” writes Mr. Sanders.

With the possible exception of a handful of cities that have long dominated the market, like New York, Chicago, Atlanta, and New Orleans and the relative newcomers Orlando and Las Vegas, “the grand promises of convention center investment are unlikely to be realized, the strategy doomed to failure,” he writes.

“Space Available” is a damning piece of work, full of facts and figures you should keep at hand next time someone suggests that your municipality should build or expand a convention center.

Mr. Sanders quotes from the feasibility studies and projections used to sell the bonds for these projects, and then from attendance numbers showing how dismally they have performed.

Even the largest, most successful venues have experienced precipitous declines in attendance. That’s because the business is contracting, as a result of industry consolidation, reductions in business travel, and alternative ways of conveying information, says Mr. Sanders. That hasn’t stopped the consultants who write the feasibility studies for these projects from claiming that expanding facilities will result in more business.

The amount of exhibit space has jumped 51% since 1990, to 60.9 million square feet from 40.4 million, according to Mr. Sanders’s report, and he says up to 7 million more square feet will be added. That would come from 22 cities that have expansions planned or under way; another 22 have new convention centers planned or under construction.

Chicago, New Orleans, New York, and Atlanta have all seen significant drops in convention and tradeshow business, says Sanders. Those are the events that bring in the out-of-town visitors who spend hundreds of dollars a day, compared with public shows, like a boat show or car show, which brings in locals. Attendance at the top 200 trade and convention shows declined from 5.08 million in 1996 to 4.08 million in 2003, says Tradeshow Week.

Even major expansions in Orlando and Las Vegas, two winners in the convention center stakes, have yielded “almost nothing in terms of increased business,” writes Mr. Sanders. Elsewhere, the drop in attendance has been “dramatic, if not catastrophic.”

How do cities justify the continuing frenzy to build these things? Bad data, for one thing, says Sanders. They rely on the analyses and conclusions of paid consultants, and on proprietary data that is impossible to verify.

That’s bad enough. Perhaps worse is what happens after these projects are finished and open for business. Public entities “report the basics of convention center performance in a wide variety of ways that tend to obscure rather than enlighten,” writes Mr. Sanders. And who can blame them? Public officials don’t want to admit that getting into the convention business was a horrible idea, and that they’ve backed a loser that just may turn into a money-pit.

The authorities that embark on these financings are almost entirely insulated from review and criticism, writes Mr. Sanders. It’s public finance, but there’s precious little public about it.

What is to be done? Mr. Sanders suggests that Congress limit the use of tax-exempt financing, with its implicit federal subsidy, for projects of more than 100,000 square feet. “The argument that the expenditure of hundreds of millions of dollars for hundreds of thousands of square feet of new convention center space in an already glutted market serves the purpose of local economic development appears rather strained,” he writes.

Maybe it’s time to change the way we think about cities and why they work, or don’t. Certainly the boom in “public sector entrepreneurship” with its emphasis on taxing, spending and building has been a marvel – but has it really delivered? Maybe cities should halt their convention center space race and invest in things like infrastructure and basic services.

“Space Available” should be required reading in every municipality that wants to bond its way to economic development.

Mr. Mysak is a columnist for Bloomberg News.