Polarization in Western democracies and the collapse of centrally planned economies have led to calls for a redefinition of the state’s core functions. This collection explores shifting conceptions of constitutional political economy anchoring the state from the viewpoints of theory, systems, and applications, with a view toward identifying why changes may be desirable and how these might be implemented. Nobel Laureate James M. Buchanan offers a foreword to the work and coauthors a chapter on theory of constitutional rules.