How does reactivity affect police behavior? Describing and quantifying the impact of reactivity as behavioral change in a large-scale observational study of police

Critics have challenged the face validity of police observational data by arguing that officers will react to the presence of the observer. This article examines the descriptive accounts of reactivity from the Project on Policing Neighborhoods (or POPN) to: (1) describe reactivity as behavioral change (i.e., officers who are more or less proactive), (2) identify why officers react in this manner, and (3) specify officer behavior susceptible to this form of reactivity. Additional analyses indicate that officers are 5.3 times more likely to be more versus less proactive. Officers are also more proactive during early stages of fieldwork and when accompanied by female observers. Finally, there is evidence of an interaction effect between time in the field and observer sex where officers are 4.5 times more likely to be more proactive during early stages of fieldwork when accompanied by female observers. The more general implications of the findings are also discussed.