Small effects, magnified over enough people, can lead to big numbers, as Highway Deaths Spike After Super Bowl demonstrates:
A study of the last 27 Super Bowl Sundays concluded that the highway death rate jumped 70% in the first hour after the big game and remained high over the next few hours.The increase was particularly dramatic in states with the losing team, where the death rate was 147% higher than on the Sundays before and after the championship.
The only exception was in states with the winning team, where highway death rates did not rise, according to Donald Redelmeier, the chief author of the study.
The scientists blame alcohol, fatigue, and distraction — “The Monday-morning quarterbacking begins Sunday, not Monday night. The result is a surge in fatality rates.”