An interrupted time-series design is used to analyze the impact of the 55 mph speed limit on U.S. traffic fatalities over the period 1950 to 1980. In addition to speed such potential effects on highway fatalities as safety improvements, decreased speed dispersion, and decreased travel are...

This research updates and extends John Crittenden's effort to identify the dimensions of modernization among the U.S. states. The objective is to determine the degree of continuity or change in the structure of modernization between 1960 and 1990. We undertake a principal-axis factor analysis of...