Your Voice Counts - Estimating the Effect of Home Crowds on Australian Football League Match Outcomes

This paper investigates the influence of crowd support on Australian Football League (AFL) match outcomes using data from 2018 to 2023, including crowd-restricted games during the COVID-19 pandemic. It finds home teams won 56.22% of games, scored 5.83 more points per game (ppg), and received 1.12 more free kicks on average than away teams—advantages that are strongest when teams travel from different cities or when the home team is ranked higher on the competition ladder prior to the commencement of the game. While overall crowd size does not correlate with match outcomes, relative crowd support (measured via membership data) does: a 1% increase in the home team’s proportion of total membership sales for competing teams is correlated with a 0.13-point increase in the score margin in favour of the home team. The paper also finds the home team winning percentage fell to 50% during games where COVID-19 restrictions prevented crowds attending games and the difference in scores between home and away teams fell to 4.234 ppg. However, a comparison of means with other types of AFL games was not statistically significant and regression analysis did not indicate a statistically significant co-efficient on “crowd lock-out†games when regressing differences in scores between home and away teams. Overall, the study suggests social pressure—particularly from crowds—can influence umpire decisions and broader match outcomes. This may support arguments for investing in independent umpire decision review systems in sport, but this must be weighed against the cost and potential to disrupt game flow from such systems. JEL classifications: C20 ; C23 ; C51 ; D71 ; L83