WASHINGTON — Federal Reserve Chairman Ben Bernanke, for fun, once mulled a way to improve baseball's earned-run average — the statistic used to assess pitcher performance.

Former Fed Chairman Alan Greenspan honed his math skills by perusing baseball data.

Economists have long been intrigued by the numbers-rich world of sports. The interest is no longer a sideline but an expanding field of study that offers insights on such broad topics as labor-management relations and racial disparities in pay and hiring.

It also examines questions such as whether football teams punt too often in fourth-down situations (yes, with implications for business risk-taking) and the lack of left-handed catchers in baseball (it's complex, but one reason is that most people who would be left-handed catchers become left-handed pitchers).

About 100 to 120 professors teach courses on sports economics, according to MKTG Services, a marketing firm. Textbooks on the subject sell well here and overseas. Dozens of sports-related papers were prepared for the recent Western Economic Association meeting in San Diego analyzing the impact of stadium announcements on property values, the winner's curse in baseball's free-agent market and other issues.

"Students absolutely eat this up. At most schools, the course is closed the day it opens," says Peter von Allmen, the Moravian College professor who co-wrote the textbook "The Economics of Sports" with professor Michael Leeds of Temple University.

"Sports, from an economic standpoint, is a fascinating industry because it's so woven into the popular culture," von Allmen adds. "People care about it in a way that they don't care about a lot of other industries that have similar or even greater economic impact."

Still, Aju Fenn, a Colorado College professor who has examined the economics of sports stadium financing, says that when he speaks at conferences, some economists slip into the back of the room with a look that suggests they should be someplace more solemn.

John-Charles Bradbury of Kennesaw State University felt compelled to defend himself and fellow economists after Chicago Sun Times columnist Greg Couch implied that some of those delving into sports statistics were frustrated geeks, or grown-up versions of the "kid who always was forced to play right field, standing there pushing the glasses back up off his nose."

"First, I don't wear glasses," Bradbury good-naturedly retorted on his blog. "Second, I was a power-hitting first baseman who once hit two home runs — the kind that go over the fence — in one game. I batted third and made my league's All-Star team."

Bradbury has a book coming out next year. "When I wrote about public finance and designed fiscal policy that would work, no one really called," Bradbury says. "I get calls from reporters all the time now. ... The market is giving me a signal."

BEHIND THE GROWTH

Economists say there are several reasons for the broadening interest. One is the growth — in attendance, salaries and revenues — of sports, including the expansion of colleges' sports management programs.

Another is the recognition that sports offer detailed statistics stretching back decades on race, salary, productivity, decision-making, financial incentives and other performance measures that aren't as available in other businesses.

"In the workplace, it's hard to measure discrimination. How do you measure productivity? In sports, there are clear-cut measures," says Colorado's Fenn.

Scholarly work in the area dates back 50 years with the publication of economist Simon Rottenberg's classic study "The Baseball Players' Labor Market" in the Journal of Political Economy. After that, there was no work published in two of the top economics journals until the 1970s, according research by to R. Todd Jewell, a professor at the University of North Texas, who outlined the evolution of the discipline in the recent "Handbook of Sports Economics Research."

Since 1990, there has been a "veritable explosion" in sports studies looking both at the market of sports and using sports data to explain or test theories about the wider business world, Jewell says.

In addition, there are now specific publications, including "The Journal of Sports Economics." David Berri, professor at California State University-Bakersfield, says another sports journal is in the works. A second leading textbook is "Sports Economics" by Washington State University professor Rodney Fort.

RESEARCH FOCUS VARIES

Research can vary from sport to sport. Economists who use National Basketball Association data tend to focus on racial issues, according to the Handbook of Sports Economics Research. Hockey literature hones in on violence and questions of discrimination against French-Canadians. Baseball, the foundation of the discipline, has such broad data that it's been used for a host of studies, many looking at the league's unique labor structure. Strategy is also a big study area.

The National Football League doesn't get as much time since it's hard to analyze data in a game where player performance is so dependent on teammates. For individual sports such as golf, tennis, track and NASCAR, economists tend to look at questions such as the best way to design contests — including efforts to examine whether men and women perform differently based on prize structure.

Edward Lazear, a Stanford University economist who is President Bush's chief economic adviser, wrote an important 1981 paper arguing that executive pay is driven by the same logic of tennis or golf tournaments. In companies and tournaments, rewards are based on relative, not absolute, performance — one player needs to play better than another to win. The more money at stake, the harder people play.

There are a number of areas where research has applications to the business world. Work on long-term contracts in sports indicates there isn't the suspected falloff in performance after deals are signed.

"If we were to find someone who has a track record of performing well (in business), we should not be deterred from giving that person a long-term contract," says John Fizel of Penn State, adding that shirking may be even less likely in companies "because you don't have the impact of injuries."

The vast reach of sports offers opportunities to examine globalization. The World Bank recently posted studies and other data on its Web site looking at the impact of the World Cup and sports and as a development tool.

A WIDER AUDIENCE

Research is moving from academic journals to a popular audience. Berri and fellow economists Martin Schmidt and Stacey Brook wrote the recently published "The Wages of Wins" in the style of the best-selling "Freakonomics" by University of Chicago economist Steven Levitt and co-author Stephen Dubner. Levitt's book uses economics in unconventional ways to examine such questions as whether parents really matter.

In "The Wages of Wins," the authors attempt to puncture some popular myths — saying payroll and wins are not highly correlated, while baseball, football, basketball and hockey attendance hasn't been significantly affected by player strikes or owner lockouts.

They've gotten some good reviews, and they've also gotten flak.

"What's interesting is how strong an opinion people have. They seem to have stronger opinions about sports than they seem to have about other things that might be important," Berri says.

Another factor in the growth: Economists, as do millions of other people, love sports.

Sunil Gulati, a Columbia University economics professor, is president of the U.S. Soccer Federation.

Yvan Kelly, chairman of the Business Administration Department at Flagler College, is a regional scout for the NBA's Seattle Supersonics, who goes to upward of 70 basketball games a season. He uses data and the more informal approach of asking around about hot prospects to figure out who to scout.

"There's still a gap between coaches willing to use statistical techniques and the people that are trying to sell it to them. ... The gap between the front office and statisticians is closing fast," Kelly says.

Players are in the mix. One of Fenn's former students is Thomas Preissing, a professional hockey player for the Ottawa Senators. While in school, Preissing wrote his senior thesis on the competitive balance in the NHL. It was later published in an economics journal.

"When you write 100 pages, you want to write about something you like," says Preissing, who found teams that spent toward the middle or bottom of the range tended to be most successful in the regular season.

"It was enlightening, but I wouldn't say I use it on a daily basis" while actually playing professional hockey, he adds.

Bill Belichick, coach of the NFL New England Patriots, was an economics major in college. He is among those who have studied University of California-Berkeley economics professor David Romer's study on fourth-down situations.