In their report, two Maryland professors also found about three-quarters of attendees came from Maryland and estimated that $10 million of the spending on restaurants and other entertainment over that Labor Day weekend would have happened even without the races as a draw.
"Based on our survey information, the Baltimore Grand Prix was certainly not a game-changer," Dennis Coates, a professor of economics at the University of Maryland Baltimore County, and Michael T. Friedman of the School of Public Health at University of Maryland College Park wrote in their report.
City officials, who are expected to release their own economic impact study in the coming weeks, took issue with the professors' analysis. They said the city's final analysis would be more comprehensive than the survey, which relied on responses from a sampling of race patrons.
The race's inaugural year came with high expectations that it would boost tourism and that media coverage would be good for Baltimore's image. But the post-race analysis has been mixed. While organizers and city officials said attendance topped expectations at about 110,000 for the three-day event, the TV audience as measured by Nielsen Media Research was one-sixth of what had been projected.
The race through downtown and past the Inner Harbor will return next Labor Day weekend, IndyCar officials confirmed recently.
Racing boosters cautioned that the city's final analysis would be the best gauge of the race's success. City Councilman William H. Cole IV, who represents downtown and was an early supporter of bringing the Grand Prix to Baltimore, said that while he wouldn't discount the professors' findings, he found their report "rushed and absolutely flawed.
"The race clearly had an impact, whether it was $70 million impact or not, I can't tell yet," he said. "They didn't take samples of hotels or restaurants or look at travel data. This was a little bit short-sighted, and I'm not sure I'd consider it adequate sampling."
The city's tourism bureau, Visit Baltimore, and research firm Forward Analytics expect to release a comprehensive economic impact analysis by late October or early November. That analysis is expected to include hotel and restaurant revenue, local contracting numbers, ticket sales, marketing and media impressions for Baltimore, broadcast coverage and parking revenue.
Tom Noonan, president of Visit Baltimore, said the tourism and convention bureau planned to review the professors' survey and show the results to Forward Analytics. "Our report will build upon the …data presented in their study to include more hard data in the hopes of providing a more complete review of the race," Noonan said in an email.
He noted that two other recent city events, Artscape and the Baltimore Running Festival, had reported economic impacts greater than $25 million — about $30 million for the festival and about $25.9 million for Artscape.
"It seems that the Grand Prix would have a greater impact on the city based on length of the event, individuals staying in hotel rooms and ticket revenue generated," Noonan said.
The race's organizer, Baltimore Racing Development, had projected spending of roughly $70 million, including spending on hotel room bookings, food, entertainment and shopping.
For the professors' report, University of Maryland students surveyed racegoers near the four entrances to the event and asked where they were from, whether they were staying in a hotel, and how much they were spending on concessions, food, entertainment, transportation and parking. Over three days, 210 surveys were completed.
More than 70 percent of respondents said they would return home after the race day, and only 9 percent said they would stay in hotels. That would translate into about 34,500 total hotel bookings, less than race organizers' initial projection of 58,000.
The professors said their findings were consistent with those on spending at similar races in other cities.
But they noted that spending during the first year may not be the best indicator of future success, and they found a number of out-of-town respondents who saw the city as a tourist destination and said they would make a return trip within the next two years.
A spokesman for Mayor Stephanie Rawlings-Blake also noted that the survey takers might have missed many racegoers staying at several downtown hotels inside the racecourse gates.
Several hotel executives have said the weekend event exceeded their expectations. The general manager of the Inner Harbor Marriott at Camden Yards has said the hotel sold out for Saturday of Labor Day weekend three weeks ahead of time.
The city-owned Hilton Baltimore Convention Center Hotel also reported strong results. Compared to the four-day Labor Day weekend in 2010, the hotel booked 473 more room nights, a 29 percent jump. It also raised its average rate by about $100 a night.
And city officials are hopeful for next year. "We still have room to improve," Cole said. "There are lots of ways to increase foot traffic to area restaurants that didn't feel the bump this year. At the end of the day, for a first year event, it was tremendously successful."