What are the most efficient strategies for authoritarian regimes to prevent the execution of coups d’état? ‘Coup-proofing’ measures have been employed by authoritarian incumbents in the Middle East and North Africa quite successfully since the mid-1970s, using substantial financial resources at their disposal generated in their rentier and semi-rentier economies. Yet, while the number of coup attempts has decreased significantly since the late 1970s, it remains unclear which forms of coup-proofing have worked best to keep officers in their barracks. Two rivaling explanations have emerged. First, political incumbents, in their bid to consolidate power, would meet officers’ demands and grievances directly and increase military spending. Alternatively, a widely accepted contention is that poverty, underdevelopment, and social injustice are associated with greater coup risk, for officers would maintain a corporate ethos to represent society and intervene in politics should that be necessary in their view. In this guise, government spending for economic development, poverty reduction, and social equality can be seen as less trivial, but potentially effective coup-proofing strategies as they ameliorate the structural underpinnings of coup risk. The paper uses two original, comprehensive data sets on military coups and government budgets to test the efficiency of alternative economic coup-proofing mechanisms. Military spending and various measures of social spending are correlated with the propensity of coup attempts executed by senior and junior officers. After controlling for various alternative explanations, robust results suggest that senior officers can be kept in the barracks through conventional coup-proofing using military spending. In turn, junior officers are less likely to stage coup attempts when social spending is high, and there is a weaker, though positive correlation with military spending. Our results reveal that incumbents have a strong incentive to maintain high military spending, at the expense of social development, to prevent coups d’état, especially attempted by senior officers. In a region rife with military intervention in politics since the inception of independent states, these findings help explain the reduction of coup attempts, but also protracted social and economic underdevelopment in the Middle East and North Africa.