The Effects of Mandatory Seat Belt Laws on Motor Vehicle Fatalities in the United States

Abstract

Objective. This article assesses the effectiveness of mandated seat belt usage. The theory of offsetting behavior asserts that when drivers feel safer, they compensate by driving less cautiously. As a consequence, any lifesaving effects from mandated safety devices such as seat belts could be significantly diminished or entirely offset. Method. This article uses regression analysis and two years (1988 and 1997) of state-level data to test for the presence of offsetting behavior by estimating models explaining total and nonoccupant motor vehicle deaths. In addition to accounting for several factors generally acknowledged as being determinants of highway deaths, the models control for the impact of primary and secondary seat belt laws. Results. The findings suggest the existence of offsetting behavior by drivers of motor vehicles. Conclusions. We need to recognize the probability of such compensatory behavior and direct our efforts at ways of ameliorating the adverse effects.

Long-run equilibrium and short-run dynamics between risk exposure and highway safety

“…Consistent with other studies (Wagenaar 1984;McCarthy 2000;Hu et al 1998;Calkins and Zlatoper 2001;Scuffhan 2003, we find a significant relationship between VMT and crashes. We could not reject the hypothesis that there is a proportional relationship between VMT and total, fatal, serious injury, and materials crashes.…”

An exploration of the offset hypothesis using disaggregate data: The case of airbags and antilock brakes

“…The majority of these tests have found evidence of offsetting behavior. But they have been conducted using aggregate data at either the national (Peltzman, 1975;Crandall et al, 1986;Chirinko and Harper, Jr., 1993;Yun, 2002), state (Calkins and Zlatoper, 2001;Cohen and Einav, 2003), county (Keeler, 1994), or city (Dee, 1998;McCarthy, 1999) level. A few researchers have used less aggregated data derived from state police accident reports (Traynor, 1993;Peterson, Hoffer, and Millner, 1995;Harless and Hoffer, 2003).…”

The costs of avoiding accidents: Selective compliance and the ‘Peltzman effect’ in Italy

“…Similarly, Houston, Richardson, and Neeley (1995), Sen (2001), and Young and Likens (2000) found that traffic fatalities in general benefit from the enactment of seat belt laws. Conversely, evidence of offsetting behaviors has been found by Garbacz (1990), and Sen and Mizzen (2007), who show a positive relationship between seat belt use and nonoccupant death rates, as well as by Calkins and Zlatoper (2001) and Risa (1994) who show evidence of a positive relationship between occupant and non-occupant fatalities and seat belt use. Some investigations, such as Garbacz (1992) and Derrig, Segui-Gomez, Abtahi, and Liu (2002), even find no relationship at all between seat belt use and traffic fatalities.…”