THERE ARE A few surprising findings in a recent report on the prospects for an expanded Pennsylvania Convention Center done by Pew Charitable Trusts.

That the scores of cities building or expanding their own centers means the competition for customers is going to be a huge challenge for our center isn't one of them.

That isn't even news: Reports and studies for years have concluded that cities have been in an "arms race" for bigger and bigger centers despite a slowing market for them. In 2005, for example, the Brookings Institution released a study claiming that public capital spending for centers has doubled over the past decade and averages $2.4 billion annually, while the market for them continues to diminish.

The Pew study, which was completed in March but only recently surfaced, analyzed current market conditions to find out what the city can expect from an expanded center. It found that the performance of the larger and more elaborate exhibit spaces that cities around the country have rushed to build, with massive public subsidies, has been disappointing. Optimistic expectations of increased visitors from new facilities - in Washington, Boston, and elsewhere - have sputtered in the face of too many choices and too few events.

Pennsylvania Convention Center, with 315,000 square feet of contiguous space, has begun demolishing buildings to make way for 228,000 additional square feet for a cost of $700 million.

Despite this, we'll still be far from one of the biggest. In 1997, our center ranked 15th in size in the country. We're now 45th. Even with expansion, we'll be 28th.

One surprising thing is why a report like this would be commissioned so late in the game; years after the expansion was planned and months after the state figured out how to pay for it. The state did require the Convention Center to do economic impact and other analyses to prove its case.

The Pew report, authored by Boston-based Economic Development Research Group, suggests that the Convention Center and its marketing arm, the Pennsylvania Visitors and Convention Bureau, might have been overly optimistic in its projections. But even that's not surprising; optimism, after all, is part of their job. (And the Brookings study suggests all cities are overly optimistic in their projections.)

Most assume that the state, which played a part in prompting the Pew study, will move to exert more control over the center's operations. Since they will bear most of the $700 million price tag, that's not necessarily a bad thing.

Another surprise is how any city or state that was paying attention to market trends would ever think expansion is a sure bet. But while cities continue to try to drag thousands of tourists and their wallets to their centers, expansion is a game no one can stop playing. (Casino supporters: are you listening?)

Convention centers don't transform cities or regions. And as Gov. Rendell himself admitted, there are many more pressing needs that hundreds of millions of dollars could fix. That's not to say a bigger Convention Center doesn't have benefits, many of which may be hard to track economically but can have long term impact. Still, we're spending huge amounts of money with little public input, and trying to keep up with an arms race that we have little chance of winning. Let's at least be honest about that. *