Economic Growth with Imperfect Protection of Intellectual Property Rights

This paper examines the growth effects of intellectual property right (IPR) protection in a quality-ladder model of endogenous growth. Stronger IPR protection, which reduces the imitation probability, increases the reward for innovation. However, stronger protection also gradually reduces the number of competitive sectors, in which innovation is easier than in monopolistic sectors. With free entry to R&D, the number of researchers in each remaining competitive sector increases, but the concentration of R&D activity raises the possibility of unnecessary duplication of innovation, thereby hindering growth. Consequently, imperfect rather than perfect protection maximizes growth. Welfare and scale effects are also examined.     

Economies with a mean demand function

The present paper shows one way to look at G. Debreu and W. Hildenbrand's conjecture that certain atomless economies have mean demand functions. We conclude within the continuity framework that an economy gives rise ‘in general’ to a continuous mean demand function, and that the class of all atomless economies is ‘big’ in the space of all economies with a continuous mean demand function. The same problems are reconsidered within the framework of a space of differentiable preferences at the end.     

Super-modularity: Applications to convex games and to the greedy algorithm for LP

L. S. Shapley (Internat. J. Game Theory1 (1971), 11–26) showed that if a game is convex, then all the marginal worth vectors are members of the core. J. Edmonds (in “Combinatorial Structures and Their Applications” (R. Guy et al., Eds.), pp. 69–87, Gordon & Breach, New York, 1970) considered a class of linear programming problems for which the greedy algorithm works. The present paper unifies these studies, and establishes the converse of each theorem.     

A profit-center game with incomplete information

Profit centers in a firm in multidivisional form agree in the ex ante stage upon a plan about their joint production and profit imputation. The plan is executed in the subsequent two periods of the interim stage: the setup period and the manufacturing period. In the setup period, each center has its private information, but a part of its information is revealed to the other centers through its action. Based on the information endogenously pooled this way, the centers take another round of actions in the manufacturing period. A core plan is defined as a Bayesian incentive-compatible plan of the grand coalition of profit centers, upon which no coalition can improve using its Bayesian incentive-compatible plan. A core plan is called full-information revealing if each center fully reveals its private information in the setup period. Three existence theorems for a full-information revealing core plan are established. The first two theorems impose alternative conditions on returns to scale: (1) the neoclassical convex technology, and (2) increasing returns to scale. In case (2), a stronger condition than Scarf's distributiveness is imposed on the total production set. The third theorem is based on a specific supplier-customer relationship among the divisions. Received: 13 October 1997 / Accepted: 26 July 1999     

Patent Policy in an Endogenous Growth Model

We investigate how the patent policy affects economic growth and social welfare based on an endogenous growth model with R&D activities. We show that the patent length that maximizes the social welfare is finite. Moreover, by introducing compulsory licensing, we also show that the patent length that maximizes the social welfare is not infinite even if the royalty rate can be controlled. Received June 29, 2001; revised version received February 5, 2002 Published online: February 17, 2003 We wish to thank two anonymous referees for their constructive comments. We also thank Akira Yakita for his helpful comments.     

A welfare analysis of global patent protection in a model with endogenous innovation and foreign direct investment

This paper constructs a North–South quality-ladder model in which foreign direct investment (FDI) is determined by the endogenous location choice of firms, and examines analytically how strengthening patent protection in the South affects welfare in the South. Strengthening patent protection increases the South's welfare by enhancing innovation and FDI, but it also allows the firms with patents to charge higher prices for their goods, which decreases welfare. However, the model shows that the former positive welfare effect outweighs the latter negative effect. Moreover, introducing the strictest form of patent protection in the South, that is, harmonizing patent protection in the South with that in the North, may maximize welfare in the South as well as in the North. Further, a similar result can also be obtained in a nonscale effect model.     

Patent protection, capital accumulation, and economic growth

In this paper, we investigate how strengthening patent protection affects economic growth in an endogenous growth model where both innovation and capital accumulation are the driving forces of economic growth. In this model, stronger patent protection raises the profit flow obtained by innovation but reduces the factor demand for capital. This process accelerates innovation but discourages capital accumulation, and because of the negative effect on economic growth through reducing capital accumulation, strengthening patent protection may then impede economic growth. This result contrasts with earlier studies where innovation is the sole driving force for economic growth. Moreover, in an open economy model where technologies are transferred and capital is imported from abroad, the strictest protection of patents enhances technology adoption from abroad but impedes capital accumulation, and thus, the relation derived between patent protection and output can be nonmonotone. In terms of implications, these findings may be able to partly explain the complex relation found by some empirical studies in this area.