“Truly free consent”? Clarifying the nature of police legitimacy using causal mediation analysis

Abstract Objectives To test whether normative and non-normative forms of obligation to obey the police are empirically distinct and to assess whether they exhibit different dynamics in terms of the downstream effects of police-citizen contact. Methods Analysing data from the Scottish Community Engagement Trial of procedurally just policing, we use natural effect modelling for causally ordered mediators to assess causal pathways that include—but also extend beyond—the experimental treatment to procedural justice. Results Normative and non-normative forms of obligation are empirically distinct. Normative obligation to obey the police is sensitive to procedurally just or unjust police behaviour, and influences cooperation with the police and traffic law compliance in a way that is consistent with procedural justice theory. Non-normative obligation to obey the police is ‘sticky’ and unresponsive. Conclusions Legitimacy can resonably be defined partly as normative obligation with its expected beneficial downstream effects, so long as it is measured properly.