In the Ph.D. curriculum, there are five clusters (principal fields). Each of the clusters represents an area of substantial faculty research interest in the School, in some cases cutting across disciplinary lines. Individual faculty choose which clusters, if any, to join; depending on interests, some faculty may wish to join more than one cluster. The faculty coordinator of each cluster assumes primary responsibility for students in that cluster.

These clusters and areas of concentration are (I) Politics and Public Policy*, (II) Political Economy, (III) Population and Public Policy, (IV) Urban Policy, and (V) Science, Technology, and Environmental Policy. 

*This Cluster is not accepting applications in the 2009 Admissions Season.