NEW YORK (CNN/Money) - On the eve of the Athens Olympics, the most pressing issue has nothing to do with security, last-minute ticket sales, or whether the concrete will dry on all those down-to-the-wire construction projects.

No, at this point the most important question is the most basic: Who's going to win? A pair of number-crunching economists have used the tools of their trade to come up with the answer.

They may be worth listening to, because four years ago, Dartmouth College professor Andrew Bernard and Berkeley's Meghan Busse made remarkably accurate predictions before the Sydney games.

Employing economics, statistics and history, they were exactly right on their advance expectations of the total number of medals (97) the United States would win Down Under, as well as the number of golds (37). They were exactly right or off by just one medal in the case of 10 other countries, too.

On the eve of Olympiad XXVII, Bernard and Busse are at it again, predicting sporting outcomes by using formulae that have little to do with athletic statistics.

Over the past 40 years, the economists say, four factors have had the greatest impact on a country's ability to win medals: per capita income, population, a record of past success, and a host effect.

"Most Olympic medal predictions assess athletic talent sport by sport and predict winners in each event," the authors write in a study published in the "Review of Economics and Statistics," an academic journal. Instead, they generalize by country, which smooths out random fluctuations based on individuals.

So, for example, if U.S. swimming star Michael Phelps, "doesn't win in 200-meter butterfly, someone else will win in kayaking," said Bernard, a professor of international economics at Dartmouth's Tuck School of Business. "All the power of the model rests on a blissful ignorance of individual sports."

"Real GDP is the single best predictor of a country's Olympic performance," said Bernard. But wealth alone doesn't explain it all.

Olympic predictions Who will win in Athens? Two economists have made these predictions. Country  Medals  U.S.A.  93  Russian Federation  83  China  57  Germany  55  Australia  54  France  37  Italy  33  United Kingdom  27  Greece  27  South Korea  27   Source:  Andrew B. Bernard and Meghan R. Busse

Size matters, too. A big population affords a country more chances to produce an extraordinary athlete. That's one reason that China wins more medals than France or the United Kingdom. Per capita incomes in those European nations are far higher than in China. But 1.3 billion people improves the odds of producing a Yao Ming.

Experience is important, as well. Countries with strong track records have an advantage over those with little past experience winning.

Finally, the economists have determined a clear home-field advantage in the medal counts. So in the last go-around, Australia did better than its GDP and population would suggest. That's good for the Greeks, who are already beaming with athletic pride over the recent success of their national soccer team.

This year, Bernard and Busse are predicting that the U.S. medal count will again be the greatest overall -- it will be 93, they say -- but that the number will decline for the third straight Olympiad. Moreover, the top 10 medal-winning countries will win fewer medals.

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That would continue a long-term trend of diminishing dominance by the big, rich nations. In 1960, according to the researchers, the top 10 countries took home 78 percent of all medals. In 2000, they took home only 55 percent.

What's happening? Well, for one thing, many poorer countries are improving their standards of living, and thus increasing their chances on the fields of sport.