Match Rigging and the Favorite Long-Shot Bias in the Italian Football Betting Market

In this empirical study, I compared the results of matches played in the Italian football league Serie A with the odds offered by bookmakers. I found that the market odds were good predictors of the actual game results, but I also found that the distribution of returns for odds' subgroups displayed the so-called favorite long shot (F/L) bias. Given the evidence of match-rigging in Italian football, I investigated if this bias was caused by a strategic behavior of bookmakers who were expecting to deal with insiders. My results support that match-rigging was associated with a larger F/L bias.