Extant evidence suggests that power-sharing reduces the participation of minorities in civil conflict by alleviating their grievances. Yet, it remains unclear how and to what degree power-sharing should be institutionalized. Moreover, direct attitudinal evidence for the grievance mechanism remains rare. Addressing these gaps, I argue that corporate power-sharing which is constitutionally-enshrined and explicitly recognizes minorities most strongly alleviates their grievances. However, it simultaneously accentuates the importance of relative inter-group comparisons. This means that minorities with a lower relative degree of corporate power-sharing than their 'peers' in the same country and transnational kin population should have higher grievances, irrespective of its absolute level. Using an extensive combination of mass survey data, I test my expectations in a series of hierarchical multi-level models. By highlighting the importance of institutional design, my results have significant implications for policy in multi-ethnic societies and for the scholarly literature on accommodation and grievances more generally.