Any normative political theory presumes an understanding of the positive processes of its proposed institutional arrangements. As such, I believe that formal theory (viz. game theory or social choice theory), by offering a better understanding of the positive processes of different kinds of political institutions, can greatly help the normative theorizing of political theorists by showing what can and what cannot be realistically achieved from the practical implementation of their proposed political theory. Formal theory can also help us clarify the precise logical relationships between fundamental normative concepts and, thereby, allow us to understand which set of normative concepts can be coherently endorsed without committing any logical inconsistencies.
You may find my "Research Statement" here.
When Liberty Dominates Patterns: A Welfare Comparison of Property Regimes under Incomplete Contracts (with Susumu Cato and Jacob Watkins-Strand) (Working Draft in Progress)
We provide a formal welfare comparison of five canonical property regimes — Nozick's right-libertarianism, Steiner's left-libertarianism, Otsuka's luck-egalitarian left-libertarianism, Rawls's property-owning democracy, and socialist joint ownership — using an incomplete contract framework parameterized by individual productive ability (θ) and cooperative surplus (α). The model yields closed-form equilibrium welfare expressions that allow systematic comparison across the full parameter space. Four findings stand out. First, among the five regimes, private ownership in any form — Nozickian, Steiner's, Otsukan, or Rawlsian — generates higher individual welfare than socialist joint ownership in most of the parameter space with the exception of Otsuka's regime: when the ability gap is sufficiently large, Otsuka's luck-egalitarian reallocation depresses the high-ability individual's investment incentives so severely even the less-able individual is worse off than under socialist joint ownership. Under these conditions, Otsuka’s regime generates the worst prospects for the worse-off that it intends to protect. Second, egalitarian regimes dominate Nozick's right-libertarianism only in a narrow Egalitarian-Dominance Zone requiring both near-equal abilities and low cooperative surplus. Third, for any positive ability gap and sufficiently high cooperative surplus, Nozick's regime Pareto-dominates all alternatives including for the least-advantaged. Fourth, the threshold of cooperative surplus after which Nozick’s regime Pareto-dominates all other regimes counterintuitively decreases as the inequality in people’s productive abilities widens. The parameter space thus partitions into three geometrically asymmetric zones: a collapsing egalitarian sliver, a larger Nozick-Dominance Zone, and a Disagreement Zone between them where the regime choice is irreducibly political. These results deliver a conditional answer to Nozick's anti-patterning challenge and identify the economic conditions under which libertarian rights and Pareto-optimality are aligned rather than in tension.
Utopia as Equilibrium: Stability, Existence, and Exploitation in Nozick’s Framework for Utopia (Prepared for Robert Nozick's Anarchy, State, and Utopia at 50' edited by Ralf Bader, Cambridghe University Press)
For fifty years, Part III of Anarchy, State, and Utopia has been admired as a flourish and neglected as an argument. I contend that it is neither: it is the keystone on which the whole edifice rests, and it can now be assessed with the formal tools Nozick himself requested. Drawing on two recent papers—“Stable Dystopia” (Analysis, 2024) and “A Formal Theory of Robert Nozick's Framework for Utopia” (Noûs, 2026)—this chapter reconstructs Nozick's possible worlds model informally and reports what the formal analysis reveals. Nozick's original circular definition of stability is indeterminate, can certify slavery as stable, can crown worlds that are best for nobody, and is in any case redundant. The non-circular alternative secures the link between stability and utopia, but at a price: it is strictly stronger than both core and Nash stability; Nozick-stable frameworks exist only under harmony conditions that suppress the very pluralism the framework celebrates; and even where they exist, they can stabilize exploitation in perpetuity, contrary to Nozick's marginal-contribution conjecture. I then develop three theses that go beyond the papers: the circular definition operates as an east-berlin of the imagination, building censorship into the very concept of stability; Nozick's meta-utopia tolerates diversity of ideals but not diversity of attachments; and the marginal-contribution conjecture fails not for want of competition but for want of prices.
This paper introduces a novel axiom—Priority—which formalizes the core prioritarian idea that benefiting the worse-off matters more. We establish the precise logical relationships between Priority and the standard axioms of distributive ethics. Three results stand out. First, Priority is logically equivalent—without any auxiliary assumptions—to what we call the Gap-Diminishing Principle, a paradigmatically egalitarian transfer principle. This shows that conceptually distinct commitments to prioritizing the worse-off and to reducing inequality impose exactly the same constraints on moral rankings. Second, under Continuity, Priority implies Anonymity: treating individuals impartially need not be assumed as a separate moral commitment, but follows from giving moral priority to the worse-off. Third, the prioritarian social welfare ordering is the only continuous ordering satisfying Priority, Separability, and Strong Pareto. We then examine what these results demand of the measurement and interpersonal comparison of well-being. Prioritarianism, so characterized, is impossible if well-being is only ordinally or even cardinally measurable and fully interpersonally comparable; it becomes possible only under translation-scale or ratio-scale measurability. Prioritarianism is thus informationally more demanding than utilitarianism. We draw out the implications for the equality-versus-priority debate and for the methodology of normative theory.
Unanimity, Sufficiency, and Coherence Across Time: An Impossibility Theorem for Intertemporal Justice and Its Escape Routes (with Kaname Miyagishima)
(Manuscript in Progress)
How should we evaluate distributions of well-being that unfold over time? We isolate three principles that any plausible account of intertemporal justice seems to need: Weak Pareto (respect strict unanimous improvements), Sufficientarian Equity (lift the persistently deprived above a minimal sufficiency threshold through a rank-preserving welfare transfer regardless of their past), and Time Consistency (today's rankings cohere with yesterday's). We prove that no social quasi-order (not necessarily complete) can satisfy all three—even when all individuals share a common discount rate. The obstruction is not the familiar equity–efficiency trade-off but a conflict between two temporal standpoints: history-blind sufficiency looks forward from the present, while temporal coherence requires that present judgment answer to the past. The result is tight: relinquishing or weakening any one principle lets an explicit social ordering satisfy the other two. We identify the cost of each escape, and prove a second impossibility showing that the forward-looking route is closed to every equity-respecting rule.
In developing a theory of first appropriation of external resources John Locke tells us that persons must leave “enough and as good” for others. This is known as the Lockean Proviso. Fleshing out just exactly what this restriction requires has been an intense source of scholarly debate, and broadly divides right libertarians – who interpret the Lockean Proviso as requiring very minimal restrictions – and left libertarians – who interpret the Lockean Proviso as requiring some form of egalitarian ownership of external resources. This paper examines and compares the economic consequences of right- and left-libertarianism (where left-libertarianism is understood as a doctrine that combines full self-ownership with what Johnathan Quong has recently called “reciprocity-based egalitarianism”) via a formal model. The results of the formal model show that everybody (including those with low productive abilities) will be better off living under right-libertarianism rather than left-libertarianism as long as the discrepancy in productive abilities between the high-ability person and the low-ability person is not too great. The upshot is that a more egalitarian ownership of external goods produced by social cooperation does not universally work in favor of those who have low productive abilities – the type of abilities caused by their unchosen circumstance for which they are not responsible.