Are perceptions of penalties stable across time? The problem of causal ordering in deterrence applied to road safety.

This study addressed the causal ordering problem in deterrence research by examining the perceptual stability of deterrence variables over time and comparing the results via cross-sectional and longitudinal surveys. This research extends upon scant previous research by including three key classical deterrence variables (i.e., the perceived certainty of apprehension and the perceived severity and swiftness of punishment), as well as Homel's (1988) extra-legal deterrence-related variables of the fear of physical loss, material loss and social sanctions. A longitudinal survey design was utilised over a three month-time period (N = 200, Mage = 20.38 years, 71 males) that examined the stability of the deterrence-related variables for three road rule violations, consisting of 1) exceeding the speed limit by more than 10 km/hr, 2) reading a message on a phone while driving and 3) using the social media platform of Snapchat while driving. Overall, fluctuations were found in all the deterrence-related variables (both legal and extra-legal sanctions), with the largest difference being for the perceptions of the certainty of apprehension. Consequently, it can be suggested that: (a) longitudinal surveys are more reliable when measuring the impact of deterrence perceptions on engagement in offending behaviour and (b) the problem of causal ordering regarding utilising cross-sectional surveys is further illuminated. The results suggest that deterrence is a dynamic process, constantly changing based upon individual experiences, which reinforces the need for continued enforcement efforts (both legal and non-legal), within the road safety arena to maximise rule compliance.