We revisit the simultaneous equations model of rebellion, mobilization, grievances and repression proposed by Gurr and Moore (1997). Our main contribution is to clarify and improve on the underlying identification strategy by resorting to the well-known colonization instruments recently constructed by Acemoglu, Johnson and Robinson (2001, 2002). We also emphasize the role played by the institutional environment. Instrumental variables estimates for post-colonial societies reveal that the strength of the state, as captured empirically by an index of bureaucratic quality, exerts a strong preventive effect on rebellion. On the other hand, working institutions also influence the likelihood of rebellion indirectly, through mobilization. Our estimates suggest that this indirect effect increases rebellion. As such, the total net effect of better institutions on rebellion is ambiguous.