桑原 史郎

This study attempts to endogenize educational efficiency, a critical exogenous parameter in the Uzawa-Lucas model, where human capital accumulation plays an important role in economic growth. Human capital accumulation is a puzzle; in addition to the broadly recognized positive spillover of human capital, educated human capital productivity occasionally shows a decreasing trend in the economic growth process (Jones in Q J Econ 110:495-525, 1995; Pritchett in World Bank Econ Rev 15(3):367-391, 2001). Incorporating these phenomena as educational externalities into the Uzawa-Lucas model, we analyze the properties of endogenous growth and stagnation. The model yields multiple steady states under intertemporal substitution elasticity larger than 1. The results reveal that a steady state with a higher growth rate demonstrates indeterminacy, and the selection of the steady states depends on expectation formation.

Kuwahara, Shiro Does international knowledge spillover always lead to a positive trickle down? This paper demonstrates the negative effects of positive international knowledge spillovers on economic growth. In other words, we obtain the possibility that educational investment for human capital is crowded out under global economic growth. To this end, we assume the phenomenon of international knowledge spillover, effects of population growth on human capital accumulation, and non-unity intertemporal elasticity of substitution in an endogenous growth model along the lines developed by Arnold. This model comprises R&D activities along the lines proposed by Jones and human capital accumulation along the lines proposed by Uzawa and Lucas. The results show that even if international spillover increases, low-growth traps without human capital investment emerge in some cases, for example, an economy with a large intertemporal elasticity of substitution and a high population growth rate. J. Japanese Int. Economies 27 (2013) 48-63. University of Tsukuba, 1-1-1 Tennodai Tsukuba, lbaraki 305-8573, Japan. (C) 2012 Elsevier Inc. All rights reserved.

Several empirical studies suggest that advanced economies experience a growth regime switch from factor accumulation to knowledge accumulation. To investigate the mechanism of such a regime switch, this study develops a concise and flexible dynamic model based on Romer (J Polit Econ 98:S71-S102, 1990) by introducing two types of endogenously supplied R&D input capital. The model replicates the growth patterns of developed and underdeveloped nations, clarifies the important role that capital plays in the difference between them, and presents several implications for interest-rate subsidies and official development assistance. Further, it shows that if a country enjoying long-run growth has little initial capital, its initial economic development will be based on capital accumulation. When the capital stock becomes sufficient for supporting R&D, the economy will achieve long-run growth through R&D.

This study develops a model wherein capital is used in final goods production and research and development (R&D) activities. This arrangement generates changes of the equilibrium capital allocation corresponding to capital endowment, which engenders a regime change from capital based growth with decreasing returns to R&D based perpetual growth. These two growth phases account for the polarization of economies. The model also engenders multiple equilibria on capital allocation-which emerge during the middle stages of capital accumulation-accounting for leapfrogging and the instability of the economic growth of developing countries with medium capital accumulation.

This study establishes an R&D-based growth model that includes the functional difference between labor and human capital in the production of goods. In our analysis, human capital is used by the managers in the manufacturing process. Such an allocation of human capital yields three possible steady states: endogenous growth, poverty traps, and multiple equilibria. Economies are sorted into these steady states according to the endowments of labor, human capital, and knowledge. Thus, the obtained steady states explain some economic growth patterns, such as polarization and leapfrogging of economies.