A longitudinal analysis of the hot hand and gambler’s fallacy biases

Abstract

Researchers have found evidence of both hot hand and gambler’s fallacy biases in lottery number selection. Which of the two opposite effects is observed is often dependent upon the nature of the lottery game, the particular sample, the local culture of the participants, or the time transpired since the seed event. By observing hundreds of millions of lottery entries over 118 consecutive semiweekly drawings, we present evidence of both effects and their longitudinal properties. With respect to the selection of individual numbers, lottery participants tend to avoid recently selected winning numbers. This gambler’s fallacy effect diminishes and the number becomes increasingly ‘hot’ until it is selected again. With respect to winning number combinations, we found strong evidence of a small but persistent hot hand bias. This bias gradually diminishes over time, but remains detectable and highly consistent for a number of years.