The University of Tokyo · Economics, Econometrics and Finance
Professor Susumu Cato's research lab specializes in industrial organization, public economics, and environmental economics, with a focus on mixed markets, privatization policies, and the role of public enterprises in economic stability and efficiency. The lab investigates strategic interactions between public and private firms, particularly in the context of market openness, environmental externalities, and long-run welfare implications. It also explores the impact of information dynamics—such as infodemics—on collective behaviors like social distancing during crises. The research integrates game-theoretic models with real-world policy challenges, emphasizing dynamic trade-offs between efficiency, stability, and sustainability.
Figures are computed from collected data and may differ slightly.
Iwai Katsuhito published an essay entitled ‘ On the 21st Century Capitalism ’ ( Iwai 2000 ) in which he reconsidered a fundamental feature of market capitalism. As is well known, Milton Friedman and his followers believed that markets and capitalism enhance not only efficiency but also stability (see Friedman 1953 ). However, Iwai claims that the two criteria are not compatible in keeping with the tradition of Knut Wicksell and John Maynard Keynes. Iwai’s principal observation was repeatedly sta
This paper investigates the long-run effect of foreign penetration in product markets on privatization policies. We find that the optimal degree of privatization is increasing in foreign penetration. This result is in sharp contrast to the existing short-run result that it is decreasing. Our result suggests that from a long-run viewpoint, the country with a more open market should promote the privatization of public enterprises, even though this reduces welfare in the short run.
The purpose of this paper is to provide a systematic treatment of tax policies in mixed markets with endogenous entry. We consider three types of tax-subsidy policies: a simple unit subsidy, an entry-license tax, and a policy mixture of the two instruments. Under the unit-subsidy policy, in contrast to the results of the short-run analysis with exogenous entry, the optimal subsidy level in a mixed market is not higher than that in a private market, and privatization affects welfare. Under the en
This study investigates the short‐run and long‐run relationships of trade and privatisation policies. In both the short run and the long run, the optimal degree of privatisation is increasing in the import tariff rate. The optimal tariff rate is strictly positive in the short run but can be non‐positive in the long run. Thus, the long‐run analysis yields contrasting implications on trade policy in mixed oligopolies.
We investigate the privatization policy of an industry where the production process generates emissions. We show that the high degree of negative externality leads to production substitution from the public firm to private firms. Moreover, we show that, if the degree of negative externality is sufficiently high, then a mixed oligopoly is preferable to a pure oligopoly for social welfare, even if the number of firms in the market is large. Furthermore, we consider free entry of private firms. I t
This debate examines the impact of infodemics - an over-abundance of information - on social distancing during the COVID-19 pandemic. Because of its external effects, social distancing behavior (SDB) shares fundamental properties with public goods, whose potential for undersupply has been examined extensively in the social sciences. Although the negative effects of infodemics have been emphasized by governments and international organizations, theoretical models suggest that infodemics may work
ABSTRACT This paper extends the classical extension theorem established by Edward Szpilrajn ( Fundamenta Mathematicae , 16, pp. 386–389, 1930). Szpilrajn's theorem states that every quasi‐ordering has an ordering extension. Because of its usefulness in various themes of economics, it has been applied by many researchers. Important generalizations have been presented by two authors, Kenneth Arrow and Kotaro Suzumura, among others. First, we provide concise proofs of four extension theorems by Szp
Abstract This paper provides an axiomatic analysis of sufficientarian social evaluation. Sufficientarianism has emerged as an increasingly important notion of distributive justice. We propose a class of principles that we label generalized critical-level sufficientarian orderings. The distinguishing feature of our new class is that its members exhibit constant critical levels of well-being that are allowed to differ from the threshold of sufficiency. Our basic axiom assigns priority to those bel
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