Ghost Games: Crowds, Referee Bias, and Home Advantage in European Football Leagues

Using a five-year data set including the crowd-less games in the 2020 English, Spanish, Italian, and German first division football leagues and multivariate regression analysis, this paper estimated how fans influence home field advantage. Consistent with previous studies, the estimates showed that in games with crowds, referees gave fewer fouls, yellow cards, and red cards but more penalty kicks to the home team than to the away team. Removing the fans from the stadium eliminated these home advantages coming through referee decisions. Removing fans reduced yellow and red cards given to away teams but did not change cards given to home teams. There was not a similar asymmetry for fouls and penalty kicks. These results suggest that crowds influenced referee judgments about how severe an infraction was more than they influenced decisions about whether a foul occurred. The addition of VAR had little impact on referee decisions and no effect on the home advantage in goal differential. Despite the home bias in referee decisions when crowds were in the stadium, fouls, cards, and penalty kicks played a relatively small role in determining home advantage in game outcomes and most of the home advantage remained after fans were removed.

The impact of COVID-19 and political identification on framing bias in an infectious disease experiment: The frame reigns supreme.

Background: Behavioral responses to the COVID-19 pandemic have become highly polarized, and public health initiatives often try to use different frames to influence behavior. If the polarization of behaviors is related to differences in responses to frames, then different health messages could be targeted to different groups to influence behavior. Objective: To determine whether risk preferences and susceptibility to gain/loss frames have been affected by COVID-19 and whether they differ along partisan lines. Methods: Using repeated cross-sectional data from a nationally representative dataset in the United States replicating the disease outbreak scenario collected before and after the onset of COVID-19, we test whether responsiveness to the gain/loss frames has changed over time and whether the responsiveness varies by political affiliation. Results: The experimental results show that the risk preferences of the U.S. population is very susceptible to the framing of choices, consistent with the literature finding risk loving preferences under the loss frame and risk aversion under the gain frame. However, the experience of COVID-19 does not appear to have changed the responsiveness, nor are there significant differences between conservatives/Republicans and liberals/Democrats. Conclusion: Targeting different partisan groups with different risk-related message frames is unlikely to be effective at altering behaviors.