The Difference Between Short and Long Run Effects of Police Outlays on Crime: Policing Deters Criminals Initially, But Later They May ‘Learn by Doing’

Abstract. In the long run a positive relationship of police expenditurescrime is derived in models which explain criminal behavior In the short run, however, the statistical results point to the possible deterring effect of police expenditures. A theoretical model is constructed to explain the statistical difference of the short and long run effect of police outlays on crime. As police expenditures increase, crime level diminishes. As time elapses, criminals may adjust to the new level of police effort, improve their performance and at the same level of outlays, increase their criminal activities. This phenomenon could be termed “Criminals’Learning by Doing”. It could explain why, over the long run, the level of crime is positively associated with police expenditures. The empirical analysis examines pooled cross sectional time series of 47 states over the period 1970 to 1980—a total of 517 cases.