Was wondering if seat belt laws would be evident in the data, just eyeballing it looks like 1989-92 decreases in motor vehicle fatalities [1] could line up with the rise of state bans starting in 1984 [2].

But seeing a pretty linear decline from 1921 to 2021 and looks like big annual drops in fatalities are more connected to economic conditions than safety features (i.e. only double digit % drops I'm seeing are 1932, 1938, 1942, 1943, 1974, 1982, and 2008).

So the drop in the late 1980s into the early '90s may've had more to do with the early '90s recession.

1. https://en.wikipedia.org/wiki/Motor_vehicle_fatality_rate_in...

2. https://en.wikipedia.org/wiki/Seat_belt_laws_in_the_United_S...