In this paper we examine the relative importance of an individual"s subjective evaluations and social capital on his/her decision to exercise social control (i.e. confront the offender) on the hypothetical instance of witnessing a PAYT (Pay-As-You-Throw) scheme violation. Our data (N=299) originates from an online questionnaire filled in by residents of Greece in early summer 2016. Through logistic regression modeling, we find that the subjective evaluation of the offence and social capital components have independent and complementary effects on the decision to exercise social control, over and above the demographic characteristics of the respondent.