A significant body of research concludes that stable beliefs of perceived consumer effectiveness lead to sustainable consumption choices. Consumers who believe that their decisions can significantly affect environmental and social issues are more likely to behave sustainably. Little is known, however, about how perceived consumer effectiveness can be increased. We find that feelings of guilt and pride, activated by a single consumption episode, can regulate sustainable consumption by affecting consumers’ general perception of effectiveness. This paper demonstrates the impact that guilt (...) and pride have on perceived consumer effectiveness and shows how this effect rests on the ability of these emotions to influence perceptions of agency. After experiencing guilt or pride, consumers see themselves as the cause of relevant sustainability outcomes. The process of causal attribution associated with these emotions influences consumers’ use of neutralization techniques. Through the reduction in consumers’ ability to neutralize their sense of personal responsibility, guilt and pride positively influence perceived consumer effectiveness. The inability to rationalize-away their personal responsibility, persuades consumers that they affect sustainability outcomes through their decisions. The research advances our understanding of sustainable consumption and identifies a new avenue for the regulation of individual consumer behavior that has significant implications for the development of sustainable marketing initiatives. (shrink)