Andersson et al. ( 2009 ) compare the prediction performance of bettors with laypeople for FIFA World Cup 2006 .
Bettors document that the performance of bettors and laypeople depends on the level of prediction tasks .
Andersson et al. ( 2009 ) compare the prediction performance of bettors with laypeople for FIFA World Cup 2006 and they document that the performance of bettors and laypeople depends on the level of prediction tasks .