This paper develops a formal model of redistributive demand with two boundaries in income–inequality space: an inequality possibility frontier (IPF), which defines the maximum feasible inequality given income relative to subsistence, and an intolerable inequality floor (IIF), above which redistribution is demanded.

Combining the IPF with Fehr–Schmidt preferences, we make the evaluation of inequality endogenous to institutions. Mobility, spillovers, contestability, entrepreneurship, and the costs of re- distribution determine whether greater inequality represents persistent exclusion or ac- companies expanding opportunities and rising living standards. Institutions therefore jointly determine both inequality and its political tolerability.

This provides a positive alternative to Law and Political Economy (LPE), which emphasizes the institutional origins of distribution and power but imports normative priors about inequality into its analysis. We show that these distributional concerns can instead be incorporated within conventional rational-choice and comparative-institutional analysis, separating explanations of redistributive demand from the normative criteria ultimately used to evaluate institutional arrangements.