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.
A Formal Theory of Robert Nozick's Framework for Utopia (with Susumu Cato)
(Revised and Resubmitted at Noûs)
This paper offers the very first formal model of Robert Nozick’s model of possible worlds and his vision of a utopian society, as outlined in Part III of Anarchy, State, and Utopia. Nozick envisioned utopia as a meta-utopia – a collection of self-organized, voluntary sub-communities – arguing that such an institutional framework is equivalent to the minimal state justified in earlier parts of his book. Nozick’s strategy was to define utopia (the best of all possible worlds) in terms of stability achieved in his possible worlds model, where individuals can create and migrate to any world they imagine. However, Nozick left many key components of this model informal and underdeveloped. This paper fills these gaps by providing a rigorous formal model of Nozick’s possible worlds. We introduce a new stability concept, Nozick stability. We demonstrate that Nozick stability imposes stricter requirements than other established solution concepts such as core and Nash stability, making the existence of a stable framework significantly more difficult to achieve. We then identify sufficient conditions for the existence of a Nozick-stable framework. However, these conditions are highly restrictive and unlikely to hold in reality. Furthermore, contrary to Nozick’s conjecture, individuals may receive far less than their marginal contribution within Nozick-stable frameworks, and, in this sense, Nozick-stable frameworks may institutionalize and perpetuate systemic exploitation. These findings cast doubt on whether Nozick’s minimal state can genuinely function as an inspiring utopian ideal, as he claims.
The Priority Axiom: A New Foundation for Prioritarianism (with Kaname Miyagishima)
(Under Review at Ethics)
This paper introduces a novel axiom—Priority—which formalizes the core prioritarian idea that benefiting the worse-off matters more. We argue that the Priority axiom offers a more direct and transparent expression of Parfit’s original insight than the widely cited Pigou-Dalton principle. We examine the logical relationships between Priority and several standard axioms in distributive ethics, including Separability, Strong Pareto, Anonymity, and Continuity. We show that under Continuity, Priority implies Anonymity, and together with Anonymity, it is logically equivalent to both Pigou-Dalton and the Gap-Diminishing principle. These results reveal deep structural links between prioritarian and egalitarian principles. We conclude by offering a new axiomatic characterization of the prioritarian social welfare ordering as the only continuous ordering satisfying Priority, Separability, and Strong Pareto. The paper demonstrates how formal methods clarify normative commitments and uncover overlooked philosophical relationships, thereby contributing both to ethical theory and the methodology of normative analysis.
Three Normative Principles for Intertemporal Justice: An Impossibility Result (with Kaname Miyagishima)
(Manuscript in Progress)
This paper investigates the normative evaluation of intertemporal distributions of individual well-being. We explore whether it is possible to construct even a partial social quasi-order that satisfies three intuitively appealing normative conditions: Weak Pareto, Time Consistency, and a form of equity we call Lifetime Sufficientarian Equity (LSE). While each condition reflects a widely endorsed normative ideal—respecting unanimous improvements, maintaining coherent judgments over time, and ensuring a minimal level of sufficiency for all individuals—we prove that these three principles are jointly incompatible. Our impossibility theorem shows that not even a partial social quasi-order can simultaneously respect all three, even under idealized assumptions such as common discounting. This result poses a challenge for ethical theories and policy frameworks that aim to balance efficiency, equity, and coherence over time, and invites careful normative analysis of which principles may be revised or prioritized.
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.