You'll need to be more specific as to the causes of the drop in violent crime in the '70s. Your example about automobile safety devices makes the dubious assum

You'll need to be more specific as to the causes of the drop in violent crime in the '70s. Your example about automobile safety devices makes the dubious assumption that manufacturers wouldn't include such technologies if not mandated by the state and that consumers wouldn't demand them. You also ignore the ridiculous amount of other required features on modern automobiles that make base models more and more expensive, hurting the lowest income levels.