Roger Noll, a Stanford professor emeritus in economics, argues sports stadiums do not generate significant local economic growth.

"NFL stadiums do not generate significant local economic growth, and the incremental tax revenue is not sufficient to cover any significant financial contribution by the city," said Noll, a senior fellow at the Stanford Institute for Economic Policy Research. He has written articles and books and given talks on the public financing of sports stadiums.

Stadium proposals for NFL teams are circulating in St. Louis, Los Angeles, San Diego and Cleveland, while San Francisco and other cities and states like Wisconsin are considering public funding for new or improved sports facilities. Local officials in Oakland, Calif., are expected to respond to a "Coliseum City" proposal in August with a December deadline for closing any deal.

Basketball and hockey arenas are a better deal for cities, he said. "Arenas are used more often."

Noll believes the current wave of stadium proposals may signal the end of an era when large "modern" venues are built.

One possibility, according to Noll, is that as professional sports generate greater revenues from Internet distribution, real-world stadium attendance will shrink, leading to smaller but more luxurious facilities.

"Another possibility is that all future facilities will be embedded in larger commercial and residential projects, with the sports team being like an anchor tenant at a shopping center," he said.