Oil and natural resource rents as percentage of GDP, with conditional effects on coup risk. Nordvik (2018) finds oil both promotes and prevents coups: windfall revenues allow regimes to buy military loyalty (rentier peace), but oil price crashes destabilize patronage networks and trigger coups. Bell (2016) confirms the conditional relationship. Ross (2001, 2012) shows oil wealth can stabilize autocracies broadly but creates brittle regimes vulnerable to external price shocks.