Abstract

A crucial challenge of governance is how rulers can establish credible oversight over local officials. Existing research highlights the importance of supervisory institutions insulated from local elite capture, but we know much less about how such oversight arrangements are built and sustained. I argue that credible oversight depends on keeping monitors organizationally separate from local society and embedding that separation in a structure of institutionalized distrust. Using Qing China as a revealing case, I show that, in minority-ruled settings, ethnic boundaries can be institutionalized as a durable basis for credible oversight, strengthening bureaucratic compliance, reducing local collusion, and ultimately strengthening state capacity. As a Manchu-ruled empire governing an overwhelmingly Han population, Qing emperors established Banner garrisons in Han-majority regions as a cross-ethnic oversight presence positioned within local administration while remaining socially distinct from local society. Leveraging the deployment of the Eight Banners Provincial Garrison System, this study uses a staggered difference-in-differences design to examine its effect on government disaster relief provision at the prefectural level. The results show that exposure to Banner garrisons significantly increased relief provision. Further tests suggest that these gains operated primarily through a cross-ethnic oversight structure, which increased deterrent pressure on local officials and improved bureaucratic compliance. Additional evidence suggests that cross-ethnic oversight fragmented local elites, weakening collusion and facilitating information revelation. This study advances the understanding of the institutional foundations of bureaucratic oversight and state capacity.