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1.
Endogenous technological change: a note on stability   总被引:1,自引:0,他引:1  
Summary. This paper demonstrates that the steady-state solution of the optimal-growth problem in Romer's (1990) model of endogenous technological change is globally saddle-point stable. Surprisingly, the proof of this result is trivial. Interest in the optimal growth path is justified by the fact that there is a (unique) combination of production and R&D subsidies by means of which the optimal growth path is attained as a market equilibrium. Received: October 6, 1998; revised version: April 19, 1999  相似文献   

2.
R&D、R&D溢出、内生增长和内生收敛   总被引:1,自引:0,他引:1  
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。  相似文献   

3.
In an earlier article in this journal I compared two R&D-stimulating policies: allowing for R&D cooperatives and providing direct R&D subsidies (see Hinloopen, 1997:Journal of Economics 66: 151–175). I also considered the implementation of both policies simultaneously. Since then Amir (1998: Discussion Paper 1/1998, Odense University) has shown that the model I used as a starting point (i.e., that of d'Aspremont and Jacquemin, 1988:American Economic Review 78: 1133–1137) is not well-defined with respect to a crucial parameter (the technological spillover) and subsequently proposes an augmentation of the model. Replicating then my original analysis with this augmented model reveals that all results stated before remain valid. In addition I correct a minor error in Hinloopen (1997) related to the comparison of optimal R&D subsidies.  相似文献   

4.
R&D spillovers and productivity: Evidence from U.S. manufacturing microdata   总被引:1,自引:0,他引:1  
This paper deals with the estimation of the impact of technology spillovers on productivity at the firm level. Panel data for American manufacturing firms on sales, physical capital inputs, employment and R&D investments are linked to R&D data by industry. The latter data are used to construct four different sets of `indirect' R&D stocks, representing technology obtained through spillovers. The differences between two distinct kinds of spillovers are stressed. Cointegration analysis is introduced into production function estimation. Spillovers are found to have significant positive effects on productivity, although their magnitudes differ between high-tech, medium-tech and low-tech firms. First version received: April 1997/final version received: April 1999  相似文献   

5.
Endogenous technological change with leisure-dependent utility   总被引:2,自引:0,他引:2  
Summary. This paper investigates the effect of introducing leisure-dependent utility into two models of endogenous technological change. Due to the flexibility in the labour supply the dynamics of the models change significantly. It is shown that if agents attach enough value to leisure in comparison to consumption two balanced growth paths may exist. This implies that economies with the same preferences and the same technology may experience different long-run growth rates. Received: October 17, 1997; revised version: January 6, 1999  相似文献   

6.
Is knowledge spillover a rationale for supporting R&D on new, emerging technologies more than R&D on other technologies? In this paper, I analyze whether innovation externalities caused only by knowledge spillovers differ between technologies of different maturity. I show that R&D should not be subsidized equally across industries when the knowledge stocks differ. This is because knowledge spillovers depend on the size of the knowledge stock and the elasticity of scale in R&D production. R&D in the emerging technology should be subsidized more when the elasticity is smaller than one. However, R&D in the mature technology should be subsidized more when the elasticity is larger than one.  相似文献   

7.
Using administrative data from firms in Australia that conduct research and development (R&;D), we examine how R&;D activity of other firms and public institutions affect a firm's own R&;D expenditure. We distinguish between the impact of peers, suppliers and clients. We examine whether geographical proximity and industrial clustering affect R&;D spillovers. Overall, we detect positive effects on R&;D expenditure from spillovers from peers and clients to firms that are nearby; within 25 or 50?km. R&;D expenditure by academia, unlike by government bodies, has a positive influence on a firm's own R&;D expenditure within state boundaries. We fail to find any significant role for industrial clusters in augmenting spillover effects.  相似文献   

8.
Summary. This paper examines the interrelationship between capital accumulation, fertility, and growth by introducing an endogenous fertility decision into Diamond's (1965) neoclassical growth model. Under the assumptions that children provide old age support and that individuals incur a variable time cost of raising children, it investigates the potential for cyclical fluctuations in the capital-labor ratio and fertility, as well as for development trap phenomena to be observed. It is shown that when capital and labor are highly substitutable in production, there is a unique steady state equilibrium, and either damped or undamped oscillations in fertility and the capital-labor ratio may occur. However, when the elasticity of substitution between capital and labor is less than one, two steady state equilibria may exist; one with a high capital-labor ratio and a high rate of population growth, and the other with a lower capital-labor ratio as well as a lower population growth rate. The former is a saddle, while the latter may be either a source or a sink. In the latter case development traps are possible. Received: June 16, 1997; revised version: December 18, 1997  相似文献   

9.
This paper investigates whether the existence of knowledge spillovers and the capacity of firms to assimilate them, which we relate with R&D intensity and some human resource management practices, are associated with the decision to innovate of Spanish firms. In order to do this, we employ data from the ‘Central de Balances’ database, which covers both manufacturing and services firms during the period 2003–2007, and use an estimator proposed by Wooldridge [2005. Simple solutions to the initial conditions problem in dynamic nonlinear panel data models with unobserved heterogeneity. Journal of Applied Econometrics 20, no. 1: 39–54] for dynamic random effects discrete choice models. The empirical exercise provides evidence on the positive link between spillovers and the innovative behaviour of companies, not just for the knowledge generated in the same industry, but also for that generated in the same region or by the public sector. Moreover, this link is stronger for those firms with a higher capacity to absorb those spillovers. This ability not only works through firms’ R&D capabilities, but also through factors such as the quality of the labour force, the share of temporary employment and the amount of resources spent in training. In addition to these factors, we find that innovation performance exhibits a high degree of inertia. Further, some other observed firm characteristics, such as size, sales growth, export behaviour, sector capital intensity or financial structure variables, are also found to be relevant determinants of the likelihood of innovation.  相似文献   

10.
A model of endogenous growth, based on Schumpeter's notion of trustified capitalism, is developed and applied to firm-level data for the period 1973–1991. The model relates the market value of a firm to its current profits and to its R&D expenditures. The relationship depends upon the expected rate of knowledge growth, the expected value of an innovation and the elasticity of the R&D production function. Over the sample period, investors expected knowledge to grow at an average rate of 5 percent, a measure which reflects both process innovations and new product discoveries. Elasticities of the R&D production functions are estimated for thirteen industry groups and interpreted as measures of technological opportunity. There is no evidence of secular decline in technological opportunity over the sample period, but there is some evidence of diminishing returns to R&D intensity. Variations in technological opportunity over time are not correlated across industries. In contrast, the expected rates of knowledge growth at the industry level are highly correlated with the aggregate expected rate.  相似文献   

11.
This paper reports results for a well established production function that includes research and development (R&D). By assuming zero depreciation, it can be used to provide estimates of excess social rates of return to R&D. The estimates distinguish spending on product and process innovations for three US manufacturing industries. The results suggest that, while excess social rates of return are found to be negative for product R&D, they are positive for process in each of the industries. They therefore suggest some scope for public R&D subsidies or tax benefits to process R&D but not to product R&D.  相似文献   

12.
This article analyses the influence of industry characteristics (concentration and technological opportunity), the institutional framework (social capital and spillovers from the public sector) and some firm factors (external and internal R&D) on product innovation in a unique integrated framework. Based on a sample of Spanish industrial firms, these variables were found to be positively related to firms’ product innovation. Also, results show that in institutional environments with significant levels of social capital and spillovers, firms change their innovation strategy focusing on external R&D.  相似文献   

13.
Patterned innovation dynamics - investment-mix shifts and inter-organizational alliances -are examined for their roles in facilitating accelelating technical advance in the telecom industry since the mid-1970s. While internal investment shifts favoring R&D and declining rates of capital recovery were ubiquitous across the period, this was especially so for telecom equipment suppliers. Comparative analyses suggest that such innovation investment strategies have been of less benefit to telecom firms than to producers in nearly any other major manufacturing sector. Trends in organizational innovation in the form of alliance fonnation are also reported. The challenges these innovation dynamics pose for neoclassical models are discussed.  相似文献   

14.
Summary. We study some implications of the Theory of Rational Beliefs to monetary policy. We show that monetary policy in a Rational Beliefs environment can have an important effect on the characteristics of economic fluctuations. In Rational Beliefs Equilibria money is generically non-neutral unlike Rational Expectations Equilibria in which money is neutral and monetary policy is ineffective. Under Rational Beliefs Equilibria nominal prices and real output change not only in response to changes in the exogenous growth rate of money but also in response to changes in the state of beliefs. In Rational Beliefs Equilibria monetary shocks have real effects even when they are observed but are not fully anticipated. Furthermore, the non-neutrality of money results in a short run Phillips curve. When money “flutters, real output sputters” [8]. We show that Endogenous Uncertainty and the distribution of market beliefs are the major explanatory variables of such fluctuations. Under Rational Expectations monetary policy is ineffective because agents neutralize it by predicting correctly the effect of the policy. Under Rational Beliefs it is shown instead that inflation and recessions can be substantially aggravated by the distribution of market beliefs. Received: January 14, 2002; revised version: April 5, 2002 RID="*" ID="*" I would like to thank Mordecai Kurz for his constant help and support. Most of the ideas developed hereby have been inspired by innumerable and fruitful discussions with him. I have also greatly benefited from helpful comments by Stanley Black, Luigi Campiglio, Carsten Nielsen and Ho-Mou Wu. I also received valuable remarks from participants at the V meeting of “The Society for the Advancement of Economic Theory” held in Ischia, Italy, on July 2-8, 2001, where an initial draft of the present work was presented.  相似文献   

15.
The purpose of this article is to show that there is a link between imperfections of competition and occurrence of endogenous fluctuations. We consider a two-sector model in which a perfectly competitive final good sector uses inputs that are produced in a Cournot monopolistic competition market. We show that when inputs are not perfect substitutes, and the depreciation rate of capital is sufficiently small, Neimark bifurcations are susceptible to emerge. This is a consequence of additional variability in the dynamical system generated by the dependence of the markup on the number of firms. This number changes over time because firms can enter and exit the market without costs. Moreover, a fixed cost in the technology ensures that the number of active firms at a given date is finite provided that the elasticity of substitution between inputs is bounded from above.  相似文献   

16.
This paper investigates the impact of R&D disclosure and finance variables on the level of R&D expenditures. The question addressed is: what is the impact of changes in disclosure requirements on the relationship between R&D expenditure and the financing of firms? The question is motivated by the possible signalling role that elective disclosure may have had prior to changes in accounting practices to ensure R&D disclosure.  相似文献   

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