Snowberg and Wolfers (JPE 2010)
Explaining the Favorite–Long Shot Bias: Is it Risk-Love or Misperceptions?
abstract:
The favorite–long shot bias describes the long-standing empirical regularity that betting odds provide biased estimates of the probability of a horse winning: long shots are overbet whereas favorites are underbet. Neoclassical explanations of this phenomenon focus on rational gamblers who overbet long shots because of risk-love. The competing behavioral explanations emphasize the role of misperceptions of probabilities. We provide novel empirical tests that can discriminate between these competing theories by assessing whether the models that explain gamblers’ choices in one part of their choice set (betting to win) can also rationalize decisions over a wider choice set, including compound bets in the exacta, quinella, or trifecta pools. Using a new, large-scale data set ideally suited to implement these tests, we find evidence in favor of the view that misperceptions of probability drive the favorite–long shot bias, as suggested by prospect theory.
大穴に賭ける動機って，「夢を買う」ってのがあるのかなぁ，と今まで思ってた。で，そういう「夢を買う」っていう動機は，risk-loverなためなのか，確率の誤解なのか，っていうこのペーパーの分類の中では，preferenceが変わるっていう意味では前者と同じ役割。そして，そういうpreferenceの変化じゃなくて，確率に関する誤解で発生するんだなぁ，ということになるわけで，直感を裏切ってくれるペーパーだ。
それはともかくとして，その2つのモデルのどちらがよりデータにフィットするのかを，単勝じゃなくて連勝を使って検証する，っていうアイデアは面白い。
