R＆D、R＆D溢出、内生增长和内生收敛

根据强调知识与技术创新、知识与技术溢出重要性的当代内生增长理论，本文建立了一个将R＆D和R＆D溢出与资本积累之间、R＆D和R＆D溢出与总产出增长之间直接关联起来的动态模型。面板数据协整检验实证分析结果表明R＆D和R＆D溢出与资本积累之间、R＆D和R＆D溢出与总产出增长之间分别存在显著的正面长期协整关联。进一步的分析表明，R＆D与资本积累之间、R＆D与总产出增长之间分别存在显著的长期双向格兰杰因果关系。由此观知，R＆D乃长期经济增长源泉之所在。另一方面，尽管资本积累或总产出增长并不格兰杰导致R＆D溢出，证据表明R＆D溢出格兰杰导致资本积累和总产出增长。这种由R＆D溢出到资本积累和总产出增长的单向格兰杰因果关系意味着尽管知识与技术的跨国传播并非必然发生。其实为世界经济增长的重要动力。     

Reexamining the interaction between innovation and capital accumulation

In endogenous growth models with innovation and capital accumulation Arnold [J. Macroeconomics 20 (1998) 189] and Blackburn et al. [J. Macroeconomics 22 (2000) 81] show that long-run growth of per capita income is independent of innovation activities; it is solely determined by preferences and the human capital accumulation technology. As a result, government policies do not affect long-run growth. This paper develops an endogenous growth model with innovation and (physical and human) capital accumulation to show that long-run growth depends on both innovation and capital accumulation technologies as well as on preferences and that government taxes and subsidies can have effects on the long-run growth rate.     

Investment-Specific R and D and the Decline in the Relative Price of Capital

The relative price of capital has declined at a rapid rate in the postwar period.This article provides a candidate explanation for this relative price decline—research and development that are embodied in new, more efficient investment goods. The model mimics the secular aspects of the data, and it has the property that the long-run growth rate of consumption is nontrivially determined as a function of the R and D efforts. Because growth is driven by investment in durable goods in the present model, it seems natural to assume that R and D is product-specific and that the firms producing these goods are long-lived profit centers that internalize the dynamic gains from R and D. A result of this assumption is that the growth rate in the decentralized economy is too low: the so-called business stealing effects that may cause the equilibrium growth rate to be too high in other models is internalized here in the form of planned obsolescence.     

Dynamical analysis of the R&D-based growth model with a regime switch

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.     

Social status, human capital formation and super-neutrality in a two-sector monetary economy

In this paper, we study how social status affects the impact of monetary policy on the long-run growth rate in a two-sector monetary economy with human capital accumulation, and find that the super-neutrality of money, with regard to the growth rate of the economy depends on the formation of human capital. In an economy with Lucas-type human capital formation, money is super-neutral; however, for an economy in which both physical and human capital are used as inputs for human capital accumulation, the money growth rate will have a positive effect on the long-run economic growth rate. The existence, uniqueness and saddle-path stability of balanced-growth equilibrium are also examined.     

Social security in a Classical growth model

This paper develops a growth model with overlapping generationsof workers who save for life-cycle reasons and Ricardian capitalistswho save from a bequest motive. The population of workers accommodatesgrowth, so that the rate of capital accumulation is endogenousand determines the growth of employment. Two regimes are possible,one in which workers' saving dominates the long run and a secondin which the long-run equilibrium growth rate is determinedcompletely by the capitalist saving function, sometimes calledthe Cambridge equation. The second regime exhibits a versionof the Pasinetti paradox: changes in workers' saving affectthe level, but not the growth rate, of capital in the long run.Applied to social security, this result implies that an unfundedsystem relying on payroll taxes reduces workers' lifetime wealthand saving, creating level effects on the capital stock withoutaffecting its long-run growth rate. These effects are mitigatedby the presence of a reserve fund, various levels of which areexamined. Calibrating the model to realistic parameter valuesfor the US facilitates an interpretation of the controversiesover the percentage of the national wealth originating in life-cyclesaving and the effects of social security on saving. The modelis offered as an analytical framework for the review of currenttopics in fiscal policy, in particular identifying the socialsecurity reserve fund as a potential vehicle for generatingcapital accumulation and effecting a progressive redistributionof wealth.     

Long-run investment under uncertain demand

In the literature investigating the impact of uncertainty on short-run and long-run investment, most authors have used a log linear profit function. This functional form has been generally considered a reasonable approximation for a more general one and has the advantage of providing closed form solutions for both short-run investment rule and long-run rate of capital accumulation. In this paper, we consider the profit function for the case of a monopolistic firm facing a linear demand function with additive shocks. Under this assumption, analytical solutions, for both short-run investment rule and long-run rate of capital accumulation, are not available. We then 1) propose an analytical approximation of the short-run investment rule and 2) show how such approximation can be used in order to derive the corresponding i) steady-state distribution of the optimal stock of capital and ii) the long-run average rate of capital accumulation. Finally, we compare the long-run rates of capital accumulation calculated under both profit function specifications. We find that, within a plausible range of parameter values, the two rates are significantly different. Hence, we conclude that the choice of a log linear functional form has a non-trivial impact on the magnitude of the long run rate of capital accumulation.     

Institutions,human capital,and growth: The institutional mechanism

This paper contributes to the debate on the relationship between human capital, institutions, and economic growth. The paper first develops a micro-foundation model linking institutions to human capital. The advantage of our modeling strategy is that the human capital accumulation function is derived from an endogenous process. The theoretical model shows that improvements in the quality of institutions foster human capital accumulation, decrease income inequality and change the historical development path. The paper uses cross-country panel data from 1965 to 2005 to test some of the model's propositions and finds that deep structures or structural institutions – which are very persistent and rooted on the historical development path of an economy – affect long-term economic performance, while political institutions are uncorrelated with productivity and long-term economic growth. The empirical estimates also show that growth of physical and human capital – instead of levels – determines long-run economic growth.     

Conflict,growth, distribution,and employment: a long-run Kaleckian model

This paper presents a Kaleckian growth model in which (i) the rate of capacity utilization, the profit share, and the rate of employment are adjusted in the medium run, and (ii) the normal rate of capacity utilization and the expected rate of capital accumulation are adjusted in the long run. The long-run equilibrium is a continuum of equilibria and is characterized by hysteresis in that the long-run position of the economy depends on where it starts. An increase in the bargaining power of workers lowers the rate of unemployment in both the medium-run and the long-run equilibrium.     

Scale Effects,Savings and Factor Shares in a Human Capital-based Growth Model with Physical Capital Accumulation

Using a balanced-growth model with physical and human capital accumulation, we analyze quantitatively the long-run effects of changes in the savings rate and in income distribution (i.e. the shares of physical and human capital in income) on investment in skill acquisition, income growth, and the ratio of human to physical capital. In the long run, the ratio of physical to human capital is constant, so that these two factor inputs can grow at the same rate. This rate is a function of the economy's exogenous technological and preference parameters and depends positively on the share of skills invested in human capital formation. We also find that population growth is neither necessary nor conducive to economic growth, that the level of real income depends linearly on the level of human capital and that it is independent of population size.