Externalities, expectations, and growth

Summary. The paper studies a model of accumulation and growth where a continuum of heterogeneous firms play dynamically optimal strategies along a (rational expectations) equilibrium. The key feature of the model is that firms' technological decisions are assumed subject to both friction and external effects. This gives rise to a wide multiplicity of equilibrium behavior, any path of sustained growth requiring that the economy tackle a never-ending chain of fresh coordination problems. This setup is modelled as a (non-atomic) dynamic game, suitable conditions being provided that partially characterize when sustained growth is a possible (never the unique) equilibrium outcome. Received: May 25, 1995; revised version: March 25, 1998     

A consumer-based model of competitive diffusion: the multiplicative effects of global and local network externalities

Competitive diffusion of two incompatible technologies, such as PC vs. Macintosh, VHS vs. Betamax and so on, is studied under the framework of a spatial game in which consumers are distributed on a two-dimensional square lattice network. The consumers play coordination-like games with their nearest neighbors and imitate the most successful strategy in their neighborhood in terms of aggregated payoffs after each round. The effects of global network externality are realized in the dynamic payoff matrix of the game, and the framework of spatial game provides the model with the effects of local network externality. These two types of externalities are set as multiplicative, that is, as nonlinear. Both simulations and mean-field approximation show that not only total but also partial standardization (robust polymorphic equilibrium) occurs depending upon the parameters and initial configurations, even when there are positive effects of both global and local network externalities. Moreover, effects of innovation factors that alter paths toward a lock-in situation are studied. It is shown that both the timing and the size of the innovation factors matter for a disadvantaged technology in order to overwhelm a market.JEL Classification: C7, D8, O3We are obliged to Professor John Paul Boyd at the University of California, Irvine and our anonymous referees for their constructive comments.     

税收征纳博弈及其行为解析

税收漏洞是促使税制完备与系统一致性的推动力。在不完备的税收制度与非一致性的税收环境中，纳税人与税收征管主体双方都必然存在对策筹划与行为抉择的战略空间。正是在这一对策均衡与非均衡的不断演绎过程中，税制才得以不断完善，从而达到系统一致性的理想境界。基于上述认识，本文着重在宏观层面上对税收漏洞问题进行行为解释与策略均衡分析，旨在从原理上构建一个税收征纳的博弈格局和对策框架。