The Measurement of Social Welfare

This paper derives a basic formula for the measure of social welfare, a second order approximation to the difference of the value of the Bergson-Samuelson social welfare function between the socially optimal resource allocation and the one in the present suboptimal economy. We discuss pros and cons of our approach for the measurement of welfare compared with other approaches to applied welfare economics, especially the measurement of deadweight loss.

On the Complementarity between Law and Social Norm: A Model Analysis with Special Reference to the Liability Rule for Tort

How the law and the social norm interact with each other in the legalized modern society, whether the law completely replaces the pre-existing social norm or they coexist, and whether their interaction achieves an efficient system of social rules or there is innate inefficiency, have remained obscure until today. This article provides an analytical model to clarify the interrelationship between the law and the social norm. We show that, where both the law and social norm maximize social welfare, their non-cooperative interaction attains Pareto efficiency and that they are perfect substitutes to each other. We then consider the case where social norm is determined on the basis of some misperceptions and show the possibility that an inefficient social system may persist. Furthermore, we illustrate the possibility that law and social norm are complements to each other and that the existence of the government could be second-best.

Socially Optimal Liability Rules for Firms with Natural Monopoly

It has been shown by Polinsky and Shavell that the strict liability rule is socially superior to the negligence liability rule when firms are injurers, strangers are victims, and accidents have a unilateral nature if prefect competition among firms prevails. This article considers the problem of socially efficient liability rules in a market where natural monopoly prevails due to decreasing average cost. We especially consider a quasi-competitive case where average cost pricing is achieved in a naturally monopolized market either through well-organized government regulation or the weak invisible hands of contestability. In contrast to the perfectly competitive economy, the present article shows that in most cases, the negligence regime is socially more desirable than the strict liability regime from the view point of economic efficiency.

Demulsification of O/W Emulsion by Weak Electrostatic Field(Poster session 1, New Frontiers in Colloidal Physics : A Bridge between Micro- and Macroscopic Concepts in Soft Matter)

この論文は国立情報学研究所の電子図書館事業により電子化されました。弱い静電場による水中油滴エマルションの解乳化 : 油滴表面に吸着したイオンによって安定化しているO/Wエマルションは,弱い電場を印加すると速やかに水相と油層に分離することを発見した。また,この現象が,油滴表面の電荷が電場によって移動したことによる,反発的電気2重層力の消滅により生じることを理論的に明らかにした

The measurement of social welfare

This paper derives a basic formula for the measure of social welfare, a second order approximation to the difference of the value of the Bergson-Samuelson social welfare function between the socially optimal resource allocation and the one in the present suboptimal economy. We discuss pros and cons of our approach for the measurement of welfare compared with other approaches to applied welfare economics, especially the measurement of deadweight loss