Experimental evaluation of public policy: the case of state legislation for child passenger safety.

Observations of children in automobiles were made in seven states before and after implementation of legislation requiring use of child passenger safety devices. Increases in safe seating for children covered by state laws and children under 1 year old were observed in three of the five states implementing legislation during this study. Decreases in safe seating for these age groups were observed in two states, however. Increases in safe seating for children from 1 to 5 years old were observed in four of these five states. Although methodological limitations require cautious interpretation, these data suggest the impact child safety seat laws may have on compliance. Implications of this research for policies on child passenger safety and the importance of exploiting naturally occurring public experiments are discussed.