Writing in The Journal of Health Economics, three economists claim (Sci Hub mirror) that "a one standard deviation reduction in daily stock market returns is associated with a 0.6% increase in fatal car accidents that happen after the stock market opening" and that this is robust across "a battery of falsification tests." They examined data from the Fatality Analysis Reporting System from 1990-2015, and conclude that this "might just be the tip of the iceberg" because most car accidents are not fatal and thus not reflected in their data-set.