Recent Evidence Based on Fatality Rate Analysis— Seven Studies

Recent Evidence Based on Fatality Rate Analysis—Seven Studies 

John Graham and Steven Garber critique what they refer to as the major previous study (Peltzman s) and offer an alternative analysis based on an updated data set with a variable which measures the extent of regulation. In their critique they demonstrate that Peltzman s model yields estimates of positive overall safety effects if the functional form is linear rather than 

John Graham uses the same regulation variable technique in another related study which covers the period 1947 to 1981. He estimates the reduced form equation for a model in which fatality rate and speed are determined simultaneously. In practical terms, the only new variable is a dummy variable for the 55 m.p.h. speed limit. Curiously the price of gas is ignored despite theory and evidence that it is a determinant of speed. This misspecification may explain the large size (39 percent for 1981) of the estimated reduction in the occupant fatality rate. He finds some weak evidence that nonoccupants are made less safe m that the (insignificant) regulation coeffident in the pedestrian 

Robert Crandall, et al. (1986) extend the earlier analysis by Crandall and report several specifications of the fatality regressions including reanalysis of Peltzman s study. The analysis in which they place the most confidence is the 

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