Assemblies and State Capacity: A Theory of Compositional Determination

Representative assemblies are held to build states by constraining rulers, yet executive constraints and fiscal capacity evolved largely independently in early modern Europe. This paper proposes a mechanism that does not run through constraint: assemblies shape state capacity through the policies they choose, whose implementation requires or starves administrative reach, so a parliament builds a state only when its composition leads it to cooperate with the sovereign rather than merely constrain him. In a dynamic game where capacity gates which policies can be attempted and accumulates only through contributions nobody can compel, four state types (nightwatchman, fiscal-military, developmental and patrimonial) arise as seat shares vary, with each group's ideal policy derived from a constrained income technology. Composition acts through the coalition that forms, not only the median: assemblies with identical medians and largest groups can reach different state types. States that start below the capability requirement of the policy their assembly demands are trapped. In the computed equilibria, under-provision is one-sided and reflects preference rather than commitment failure. Several results are numerical rather than proved. The outcome is capacity, not development.