Urbanization is going on in China. This paper considers the optimal process of urbanization in a theoretic framework. We already have the Henry George theorem, which asserts that the optimal amount of the public goods should equal the total amount of land rent for the optimal distribution of the...

We consider cannibalization in a duopoly model in which …rms with di¤erent costs supply two vertically di¤erentiated products in the same market. We …nd that an increase in the di¤erence in quality between the two goods or a decrease in the marginal cost of the high-quality goods leads to...

This paper examines how pay-as-you-go (PAYG) pension reform from a defined-benefit scheme to a defined-contribution scheme affects economic growth in an overlapping generations model with endogenous growth. We show that in economies in which the old-age dependency ratio is relatively high and...

We develop a model in which a `genuine' producer supplying genuine products competes with many `non-genuine' producers supplying the compatible third-party or generic products. We examine whether non-genuine products should be expelled from markets. In particular, we focus on the genuine...

We provide a simple model of endogenous product compatibility choice under Cournot competition with a network externality. Using the model, we consider how the degree of a network externality and product substitutability affects the choice regarding product compatibility. In particular, if the...

This paper constructs a simple Malthusian model to explain per capita income differences in the Malthusian era by focusing on regional variations in the expansion of the commercial sector. This paper shows that a larger productivity improvement in the skilled intensive commercial sector relative...

This paper first presents the optimal conditions for strategic R&D investment policy in the cases of noncooperative and cooperative R&D investment policies with international rivalry. Then we deal with a model of strategic product (i.e., quality-improving) R&D investment competition. In...

In economically developed countries, aging of the population with fewer children is progressing. Social security benefits such as pensions and elderly care are increasing. In a society with fewer children, it is difficult for a government to provide sufficient pension benefits for older people...

We investigate a Stackelberg oligopoly model in which m leaders and N-m followers compete. We find an asymmetric welfare implication of the Stackelberg model. Introducing a small number of leaders into the Cournot model can reduce welfare. However, introducing a small number of followers into...

In this paper, we consider a duopoly model where two firms sell two differentiated products and there is a network externality between either carriers or machines. We derive the equilibria of these games and illustrate the effects of a change in quality on the equilibrium quantity of each good....