Fair Week anywhere is economic stimulus dressed up as a plump 4-H pig.

More cars and out-of-town visitors on the streets mean a fresh infusion of cash making the rounds at local businesses.

In Casper, a stroll downtown on Parade Day revealed cars from Minnesota, Texas, Colorado, Nebraska, South Dakota, a yellow sports car probably from Georgia, and a Clydesdale van from Missouri. Six Wyoming counties also were represented.

But whether the mix of license plates would have been different on any other summer day is anyone's guess.

Even during Fair Week, a dozen drilling crews from Oklahoma could suddenly turn up at the Wonder Bar, which would skew such casual statistics and be completely unrelated to the Central Wyoming Fair and Rodeo.

The best way to figure out the economic impacts of fairs and rodeos is via what Dick O'Gara, president of the Wyoming Center for Business and Economic Analysis in Cheyenne, calls an intercept survey. He has conducted such studies to gauge the economic benefits of Frontier Days.

To collect data, interviewers stop fair and rodeo goers at event entrances, in some randomized fashion. Visitors then are asked a series of questions: Where are you from? Where are you staying? How long do you plan to stay? How many rodeo events do you plan to attend? How much will you spend on lodging, food, gas and the like? The interview process can take about 20 minutes.

O'Gara said answers to such questions allow researchers to calculate the economic activity generated by the event.

Sometimes, event boosters don't like the answers. People who claim Frontier Days draws 250,000 visitors are wrong, O'Gara says: "Not even close."

His research in the 1990s suggested the real number is closer to 80,000 individuals for the week.

"If you put a quarter million people in Cheyenne, you aren't going to be able to move," he said.

At the time he conducted his Cheyenne Frontier Days surveys, the economic activity attributed to the event was calculated at about $20 million.

In addition to estimates of total economic impacts, such studies can help guide marketing efforts by identifying visitor points-of-origin, which allows targeted advertising in those areas.

Last year, the Central Wyoming Fair and Rodeo recorded 126,000 visits, according to Angela Berry, who works in marketing and promotions. Included were 25,000 visits to the rodeo. "We count visits, not people, as they spend money each time they come through the gate," she said.

"We sell gate passes and rodeo tickets," she added. "Fair goers would just need a gate pass, and rodeo goers need the rodeo ticket which includes the gate fee."

Employees stationed at each gate do keep a tally of license plates to determine visitor places-of-origin.

"Last year, all states were represented except Hawaii, and all counties from Wyoming were represented," Berry said.

Visitors are not actually interviewed, but they are asked to complete questionnaires handed out at the gates. The questions are related to fair experiences rather than economic impacts.

Berry said the last economic analysis of the fair was conducted about 10 years ago, when the economic benefit to the community was estimated at about $4.5 million.

Business Editor Tom Mast can be reached at tom.mast@trib.com, or call 307-266-0574. Or check out his "Two Bits Worth" blog at tribtown.trib.com/TomMast/blog