The Indiana State Fairgrounds generated $124 million in visitor spending in 2011 and has an annual impact on the local economy similar to a factory employing 500 people, according to a study released Wednesday.

“There’s really nothing in Indiana that’s quite comparable to the state fairgrounds,” said study author Bruce Jaffee, Indiana University professor of business economics, in a prepared statement. “Its impact is different from something like the Super Bowl or a Final Four because it’s not a one-time occurrence.  It’s an economic engine generating spending, revenue and tax receipts year after year.”

In his study, Jaffee likened the fairgrounds to a manufacturing plant with 500 to 600 employees and per-employee revenue of $300,000 per year.

The latest study follows one in 2011 that found the Pepsi Coliseum at the fairgrounds generated $89.3 million in spending, with $73.3 million of that coming from out-of-town visitors. The 73-year-old coliseum accounts for 40 percent of the fairgrounds’ year-round operating revenue.

The Indiana State Fair Commission recently approved a plan to expand the coliseum’s seating from 8,000 to 9,000 by 2014. The renovation is slated to start this fall.

Now the commission is looking to draw attention to the fairgrounds for its year-round events.

“People know all about our wonderful fair, but hundreds of other year-round events draw millions of people to Indianapolis, and that results in an important economic boost to our area businesses and tax revenue,” Indiana State Fair Commission Chairman Andre Lacy said  in a prepared statement.

Jaffee took a conservative approach with the study by separating spending by visitor and local residents. The $124 million was spent by out-of-county visitors. Marion County residents spent another $34.4 million at the fairgrounds last year, he found. That money was likely to have been spent in Indianapolis anyway.

Jaffee did not calculate indirect spending by people who make money from the fairgrounds but said that could double the total impact.

The 17-day Indiana State Fair accounted for nearly 21 percent, or $26.2 million, of the fairgrounds-generated spending. That was up almost $7 million from 2001, the last time a study was conducted.

Fair attendees also generated more “balanced” spending, both inside and outside the fairgrounds, Jaffee noted. About three-quarters of the $124 million in visitor spending takes place inside the fairgrounds, the study said.