Economists tend to favor prediction markets—in which people bet against each other to predict an outcome—over prediction polls—in which guessers essentially bet against themselves. But a new study from the University of Pennsylvania found prediction polls actually tend to fare better.

 “According to the theory, prediction markets should ‘always win’ because markets are the most efficient mechanisms for aggregating the wisdom of a crowd. That process should converge on a true prediction,” said Philip Tetlock, a Penn Integrates Knowledge professor. “But our findings published in Management Science suggest that you can actually get just as much out of a forecasting tournament using prediction surveys.”

The study found that team polls, in which groups of up to 15 people collaborated to make forecasts, produced the most accurate predictions when combined with a statistical algorithm.

“We used each person’s prior track record and behavioral patterns to come up with a weighting scheme that amplified those who were more skilled and lowered the voices of the less skilled,” said Pavel Atanasov, a former Penn doctoral student and the study’s lead author, who currently works on decision science and prediction at a startup called Pytho. “Accounting for skill improved the overall results.”

Funding for the work came from the Department of Interior’s Intelligence Advanced Research Projects Activity, Carnegie Corporation and Open Philanthropy Network.