"The building will take you only partway," Wieland acknowledges. "Once everyone sees the building, it's the program that brings people back. The pressure is on Michael [Shapiro, the High's director]." Pressure is also on Sharp, in Denver. Last year Hamilton persuaded him to delay his planned retirement and sign a new contract. "I wanted to make sure we had this all blocked out for the next five years, so we have a good product to sell," the oilman says. "He'll be here for five more years or I'll kill him."

Anyone who doubts the importance of programming need only look to Cincinnati. When the new Contemporary Arts Center was being planned there, donors spoke admiringly of the Guggenheim Bilbao's economic impact, and they thought big. One trustee told the Cincinnati Post that the number of visitors to the CAC's new home could reach 375,000 a year (a figure later scaled back to 180,000). After all, Hadid, the architect they hired, was very hot, and this was her first building in the U.S. She delivered a beauty, much praised by critics everywhere.

Attendance rose from 35,600 to only about 84,000. Then it fell to 54,000. Long before that, however, the board had replaced director Charles Desmarais with Linda Shearer, from the Williams College Museum of Art. Last September, Shearer resigned, with bad feelings all around. Trustee Richard Rosenthal says she was wrong for the job. "There were shows done that did not have the attendance we would like," he explains. "They were beyond the reach of what our patrons and our constituency wanted to see. That is not to say they weren't good shows." Rosenthal notes that the board is now shooting for 60,000 to 70,000 visitors a year. "We're not retreating. We are still doing cutting-edge exhibitions, but we're mixing them with others." In May, trustees hired a new director, Raphaela Platow, from the Rose Museum of Art, in Waltham, Massachusetts.

The fact that many museums can now, for the first time, offer a broad menu of shows is one positive outcome of the expansion frenzy. At the High, Stent says, "We can do three or four exhibitions at the same time." Sharp sees benefits for other areas, as well. "We are into more ambitious shows and special-event programming," he explains. "We want those types of activities—events and exhibitions that are complementary. We want it to be not ‘Let's go down to the Denver Art Museum to see a great Impressionist show,' but ‘Let's go down to the museum because there's always something going on there,' and the Hamilton building is part of that."

But Ellis fears everyone is missing the point. He says many museum trustees—and outsiders, like state and local governments, that provide support—don't understand museum economics. The increased admission fees that usually accompany attendance gains can't cover the increased costs of enlarged buildings. Bigger structures mean more money is needed for everything from staffing to exhibitions to education programs. In Denver, security costs alone almost doubled. The High's operating budget ballooned by more than half between 2005 and 2007. And most museums, Ellis says, reap less than 10 percent of their operating budget from the gate. So even doubling attendance—not an easy feat—doesn't help much.

As a result, the new, improved museums tend to spend a few years trying to balance the budget. They can't trim security, energy, or insurance costs, so they cut back on conservation, acquisitions, and curatorial staff. "Subtly, the ratio between fixed costs, which are about the building, and variable costs, which are the programmatic costs, has changed," Ellis notes. "And that means more building and less art."

The economics also affect the kind of programming that is done. Museums may feel pressured to take more touring or for-profit exhibitions, like the current King Tut blockbuster, or mount pop-culture displays of Star Wars memorabilia, hip-hop artifacts, or motorcycles rather than academically grounded efforts.