In an era of devolution, collaboration between state and local institutions could be an effective tool for state governments to capitalize on local knowledge and respect local autonomy, while maintaining consistent standards and enforcement. However, the benefits to local agencies are less clear. Local agency personnel may have goals that diverge from their state counterparts and significant constraints on their resources, forcing them to consider the opportunity costs of collaboration. This article examines the determinants of subnational vertical collaboration in two settings: nested institutions with parallel missions and institutions with separate, but overlapping, missions. Augmenting an original survey of local public health departments in Wisconsin with data from other sources, we simultaneously estimate models predicting local cooperation with state agencies within and across issue boundaries. Our analysis indicates that management techniques, particularly performance evaluations that are tied to collaborative efforts, are the strongest determinant of collaboration across levels of government. We also find that political context facilitates vertical collaboration across nonnested institutions. Within nested institutions, local agencies are more likely to work with their state counterpart if they lack the capacity to act alone. © The Author 2009.