TOM WALSH: Super boost for Detroit Big game had $273.9-million overall impact March 16,

Economic Boost Hosting Super Bowl XL provided a $273.9-million economic boost to the Detroit area, according to the just-completed study by a St. Louis research firm for the Metro Detroit Convention and Visitors Bureau. That total is at the low end of the range between $262 million and $342 million that the National Football League had projected before the big game. That's because many Pittsburgh Steelers fans from Pennsylvania, who outnumbered visitors from the Seattle area by more than 3-to-1, had short hotel stays or traveled in recreational vehicles that they parked at the Pontiac Silverdome or Eastern Market.

Out-of-town Spenders Each out-of-town visitor spent $363 a day on average, not including airfares, lodging or tickets to the game. The biggest beneficiaries of Super Bowl spending were the region's hotels, the casinos and other entertainment spots, and food and drink providers. Among them, these businesses took in 54% of the $170 million in direct spending by out-of-town visitors, according to the study by Sportsimpacts, a research firm run by Patrick Rishe, an economics professor at Webster University in St. Louis.

Leakages The overall economic impact figure of $273.9 million is greater than the direct spending by visitors because it includes the pass-along effects of extra spending by Detroit-area businesses and employees who quickly re-spent the extra money they took in from visiting Super Bowl fans, Rishe said. Conversely, some of the economic benefits -- about $98 million, he estimated -- leaked away from the Detroit area because profits from casinos, Super Bowl merchandise and some hotels go to companies based elsewhere.

Net Effect Even after subtracting an estimate of whatever wining, dining and gambling would have gone on during Super Bowl weekend in Detroit even if the game were not here, Rishe said the smallest net impact would be around $125 million or $130 million. "This means that roughly 70% to 75% of the economic activity that occurred in metro Detroit during SBXL weekend would not have occurred had metro Detroit not been hosting SBXL," Rishe concluded in his report.

Economic Critique (+273.9/170) implies a multiplier of  not really plausible in a three day period. To say that 70 to 75% of the activity would not have taken place is to imply that activity was 3.3 to 4.0 times as large as on a normal Super Bowl Weekend … also implausible.