Using a National Bureau of Economic Research dataset of employees of 14 United States companies with shared capitalism practices, we compare two prominent explanations of employee ownership’s influence on pro-organizational behaviors—psychological ownership and alignment of financial interests—by testing the effects of Employee Stock Ownership Plans (ESOPs) and current profit sharing on promotive voice. We conducted a path-analysis of a moderated multiple-mediation regression model using the PROCESS macro. Our sample included 16,557 participants. We find that psychological ownership partially transmits the effects of ESOP participation and current profit sharing on promotive voice. Employee decision influence strengthens the relationship between ESOP participation and psychological ownership. Perceived alignment of interests does not mediate the relationships between employee ownership and promotive voice.