The degree of association between the upswings and downswings in the Swiss national economy in the period 1963-1993 and the changes in the traffic accident rate were investigated by means of analysis of multiple regression and of auto-regressive and integrated moving averages (ARIMA). The variations in economic prosperity were measured in terms of employment and unemployment statistics and the index of industrial production. Changes in population characteristics were accounted for by consideration of the proportion of young people in the total population. The dependent variables were primarily the rate of traffic fatalities per head of population and property damage as experssed in insurance claim records. Coefficients of multiple correlation were found to be .97 for the fatality rate and .96 for property damage. There were some differences in the degree of predictability of different types of accidents (pedestrians versus others) and the fatal accident rate in different age groups. ARIMA analysis of the association between the index of industrial production alone and the fatal accident rate resulted in a cross-correlation r = .96 on the basis of annual data and r = .95 on quarterly data. In periods of relative economic prosperity, the rate of fatalities and property damage in traffic were found to be higher, the suicide and homicide rates lower, the overall fatal accident rate (in traffic and elsewhere) higher, the violent death rate higher and the aggregate mortality (regardless of the cause of death) lower.
Samenvatting