Social pressure in football matches

Our behavior is highly influenced by social stress. This column takes it as a normal test of the 2020 season of the Japanese Professional Football League, where matches were held without spectators due to the Kovid-19 epidemic, to test whether the presence of spectators puts pressure on the referee’s decision. The authors see that the advantage of the home team is real: the number of fouls decided against the home team in matches with the spectators has decreased significantly. The perfect number of home-team supporters is important.

Our behavior is highly influenced by social stress. In Japan, for example, during the COVID-19 epidemic, many people stayed at home and wore masks, following the government’s ‘request’ even though they were not legally bound. Such behavior may be due in part to social stress in addition to the primary purpose of infection prevention.

The relationship between social stress and human behavior has been a major concern in economics since the pioneering work of Akarlof (1980). A strand of literature has analyzed this relationship by focusing on spectator attendance and match outcomes in professional games (e.g. Andrich and Geshey 2020, Bryson et al. 2021, Skoppa 2021). We follow this literature (Marita and Archie 2021) and take the 2020 season of a Japanese professional football league as a natural test, which was unexpectedly forced to hold matches without spectators due to the Covid-19 epidemic, to check if spectators were present. The referees put pressure on the decision.

‘Remote match’ in Japan

In Japan, a match without spectators due to an epidemic is called a ‘remote match’. The 2020 season began on February 21 and only the first episode of the season was held as usual. After the first period, the season was postponed until June due to the spread of Covid-19. Matches resumed on 4 July for the first division (J1 league) and 27 June for the second division (J2 league) but were held without spectators and the situation continued at a later time in early July. As a result, 43 of the 768 games (5.6% of all games) were played as distant matches. This means that – based on the 2019 season – an average of 21,000 spectators per match was removed from the stadium in J1 and 7,000 spectators per match in J2 during this period. Taking advantage of this unprecedented situation, we analyze whether the referees’ decisions, such as fouls and yellow cards, are influenced by the social pressure of the spectators.

After 10 July 2020, the limitation on the number of visitors was gradually relaxed depending on the transition situation, as shown in Table 1. Roughly speaking, the two matches were held as completely distant matches after the matches resumed and then for some time, only home-team supporters were allowed to watch the game in the stadiums under the strict attendance cap (Step 1). After a transition period, away-team supporters were also allowed to enter the stadium and the attendance limit was further relaxed (steps 2 and 3).

In short, in the first stage, the number of spectators was low but the stadium was 100% full by home-team supporters. In contrast, during the second and third rounds, the absolute number of home-team supporters at the stadium increased but their proportion decreased due to the gathering of away-team supporters. We focus on the differences in audience limitations and identify whether referees have shown bias and whether the source of any such bias is the exact number or proportion of home-team supporters.

Table 1 Timeline of restrictions on visitors

Referee bias

We use differences to estimate the impact of home-team supporters on referees’ decisions. This approach emphasizes the advantages of the home team – in the form of referee decision making – arising from the presence of home-team supporters. It captures the difference between (i) without the spectator and (ii) with the spectator (Figure 1) during the match between the home team and the away team.

Figure 1 Differences

Comments: This figure shows the difference between the differences graphically. The difference (i) corresponds to the difference in the number of fouls for the home vs. away team in a match without spectators, while the difference (ii) matches the difference in the match with the spectators. Our interests are in line with (i) – (ii).

The analysis reveals that the number of fouls decided against the home team in matches with spectators has dropped significantly, to around 1.05, indicating that the home-team advantage is statistically significant even though its scale is small. On the other hand, the number of yellow cards received by the home team was not affected. Moreover, the importance of the perfect number of home-team supporters based on the power limitations of the stadium was clear: we noticed significant advantages of the home-team in the referee’s decision when matches were played under relatively relaxed restrictions on spectator caps. Supporters of the team away. However, the referees’ decision only caught 1.37 fouls as an advantage for the home team.

Conclusion

We have examined the effects of social stress on human behavior by applying the natural test of professional football league matches without any spectators under the COVID-19 epidemic. Based on the information about the detailed differences in visitor limitations, we have extracted the effects of restrictions with a reliable identification strategy. Our work is an empirical analysis that supports the classic economic theory of social behavior, presenting an uninterrupted line of literature from the pioneering work of Akerloff (1980).

The power of social pressure is not unique to referees ’decisions in sports matches: it can also apply to peer pressure under the Covid-19 epidemic that forces people to wear masks and refrain from going out. Therefore, it is advisable to clarify the relationship between social stress and human behavior through the evaluation of such phenomena.

Editor’s note: This column is based on the main research that (Morita and Archie 2021) was first published as a discussion paper by the Institute of Economics, Trade and Industry Research (RIETI) in Japan.

References

Akerlof, GA (1980), “A theory of social norms that may result in unemployment”, Quarterly Journal of Economics 94 (4): 749.

Bryson, A, P Dolton, JJ Reade, D Schereyer, and C Singleton (2021), “Causal effects of absenteeism on performance and referee decisions during Covid-19”, Economic letter 198: 109664.

Endrich, M, and T Gesche (2020), “Referee’s decision home-bias: evidence from ‘ghost match’ during Covid-19-epidemic”, Economic letter 197: 109621.

Morita, H, and S Gesche (2021), “Social Stress in Football Match: An Event Study of ‘Remote Match’ in Japan”, Applied economic letter (Upcoming).

Scoppa, V (2021), “Social Stress in Stadiums: Do Agents Change Behavior Without Crowd Support?”, Journal of Economic Psychology 82: 102344.