The role of diminishing returns in neo-Schumpeterian growth theory

Summary. This paper generalizes Segerstrom [5], a dynamic general equilibrium model of endogenous growth through quality improvements in which innovation and imitation are modeled as the outcomes of research and development (R&D) races. Specific factors introduced into the technologies of both R&D activities achieve diminishing returns to scale in R&D. The comparative-static results of subsidies to R&D activities depend on the degree of diminishing returns to scale in R&D. When there is (is not) a sufficient degree of diminishing returns to R&D, a subsidy to innovative activity increases (decreases) innovative activity. Received: July 8, 1994; revised version: June 9, 1997     

Population and Economic Growth Under Different Growth Engines

Using a growth model with physical capital accumulation, human capital investment and horizontal R&D activity, this paper proposes an alternative channel through which an increase in the population growth rate may yield a non‐uniform (i.e., a positive, negative, or neutral) impact on the long‐run growth rate of per‐capita GDP, as available empirical evidence seems mostly to suggest. The proposed mechanism relies on the nature of the process of economic growth (whether it is fully or semi‐endogenous), and the peculiar engine(s) driving economic growth (human capital investment, R&D activity, or both). The model also explains why in the long term the association between population growth and productivity growth may ultimately be negative when R&D is an engine of economic growth.     

NON‐SCALE EFFECTS OF INTERNATIONAL TECHNOLOGICAL‐KNOWLEDGE DIFFUSION ON SOUTHERN GROWTH AND WAGES

We develop a dynamic, general equilibrium non‐scale endogenous growth model of North–South technological‐knowledge diffusion by imitation. Countries differ in levels of exogenous productivity, human‐capital levels and R&D capacity. Growth is driven by Northern innovative R&D and the South converges towards the North. Growth is also driven by human‐capital accumulation, scale effects are removed, imitation is only feasible once a threshold distance to the frontier has been attained and is dependent on the South's relative level of employed human capital and on domestic policies promoting R&D. Imitation promotes partial convergence of inter‐country wages and governs the path of intra‐South wage inequality.     

Effect of the Tax System ON R&D Intensity,Growth, Wages and Consumption Share

We propose a general equilibrium knowledge‐driven (semi‐)endogenous‐growth model with horizontal R&D, which is extended to consider two types of labour, skilled and unskilled, and exogenous government expenditure, financed through taxes on financial assets and on labour income, to analyse the implications of the tax system on R&D intensity, economic growth, wage inequality and consumption share in the output. In particular, we show that: (i) taxes have negative influence in the consumption share, being higher the marginal effect of the labour‐income tax; (ii) for any given government expenditure share, an increase (a decrease) in financial‐assets tax decreases (increases) the labour‐income tax; (iii) only the financial‐assets tax affects negatively the R&D intensity and the skill‐premium; thus, to reduce the skill‐premium the financial‐assets tax must increase; (iv) ignoring the effect on wage inequality and on R&D intensity, taxes are substitutes.     

How Important Are Scale Effects for Growth When Knowledge Is a Public Good?

In this paper, by proposing an R&D accumulation law for an economy with an expanding number of firms, I seek to reconcile the following three facts: the positive relationship between the fraction of income allocated to R&D expenditure and growth; the positive relationship between the number of firms and total factor productivity growth; and knowledge as a non‐rival and non‐excludable good. There are scale effects because of the public nature of knowledge, but the economy also grows in the absence of population growth. I find that population growth explains one‐fifth of market income growth but only one‐sixteenth of efficient income growth.     

Effects of a blocking patent on R&D with endogenous survival activities

This study analyzes the effect of strengthening patent protection for innovation and economic growth by introducing a blocking patent into the endogenous growth model developed by Furukawa (Econ Lett 121(1):26–29, 2013a), which features survival activity of patent holders in the R&D sector with a variety-expansion model. Results show that strengthening patent protection can raise the economic growth rate and social welfare through an endogenous survival investment. Additionally, this study examines the effects of increasing subsidies for R&D. We find that increasing R&D subsidy rate can negatively affect economic growth and social welfare because of the investment for survival activities. This result shows the novel role of a blocking patent in determining innovation effects of R&D subsidies. Furthermore, we analyze the effect of patent breadth which is another patent instrument in this model on innovation and economic growth. Results show that the growth and welfare effects of the profit-division rule and the subsidy rate for R&D may vary with the size of patent breadth.     

International,intersectoral, or unobservable? Measuring R&D spillovers under weak and strong cross-sectional dependence

In the theoretical and empirical growth literature, private and social returns to R&D have been identified as the key drivers of productivity gains and economic development. However, recently the debate on the relative importance of private vis-à-vis social returns has been reinforced by contributions in two emerging fields of the applied econometric literature, namely spatial panel modeling and the common factor approach, which stress the role of cross-sectional dependence as a source for a potential estimation bias linked to the measurement of returns to R&D. In this paper, we account for these methodical advances when estimating sectoral knowledge production functions for OECD countries under weak and strong cross-sectional dependence. By doing so, we are able to uncover technology- and trade-related R&D spillover channels associated with social returns to R&D, while effectively controlling for other types of productivity spillovers and latent macroeconomic shocks. Our results highlight the role played by international-intersectoral R&D spillovers for the social rate of return to R&D, while we get limited evidence for private returns to R&D once cross-sectional dependence is properly accounted for.     

Learning-by-doing in R&D, knowledge threshold, and technological divide

This paper presents a simple R&D-based growth model of the “technological divide,” in which learning-by-doing (investing) in R&D and a threshold level of technological knowledge jointly determine the pattern of economic growth. Specifically, the model generates differences in the growth pattern primarily by modifying the underlying parameters that govern the evolution of economy-wide technological competence or dynamic R&D productivity. The technological divide arises at the threshold level of technological knowledge, which is largely affected by the quality of socio-technological infrastructure. Government policies aimed at enhancing the quality of socio-technological infrastructure can help countries escape from the “technology divide” trap by lowering the knowledge threshold. While the model preserves the spirit of the R&D-based endogenous growth model in the sense of its policy effects and the endogenous evolution of technological competence, the model does not need to reach the scale effect directly, where an increase in the size of an economy generates more rapid growth.     

The spillover effects of innovative ideas on human capital

This paper extends a two‐period overlapping generations model of endogenous growth where the interactions between public infrastructure and human capital with research and development (R&D) activities and growth are studied. The paper makes two important contributions. First, it accounts for the spillover effect of the stock of ideas on learning, which in turn promotes the production of innovative technologies. In doing so, it brings to the fore a two‐way interaction between human capital and innovation. The paper then applies various econometric methods which confirm the above theoretical thesis. Second, the solutions of the model emphasize the important role public spending on infrastructure, human capital and R&D can play in promoting economic growth. However, the findings also show that trade‐offs in the allocation of public spending may inevitably emerge. In particular, investment in public infrastructure at the expense of spending on R&D is less likely to succeed in promoting economic growth, whereas it may be more effective to foster growth through an offsetting cut in another productive component, namely, education. In light of these potential trade‐offs, governments in low‐income countries need to use their limited budgets as part of holistic measures in order to achieve efficient outcomes.     

教育、创新与经济增长

由于知识的非竞争性,基于R&D的内生增长模型存在规模效应,即人口数量越大,从事R&D的人员越多,经济增长率越快。本文将R&D人员创新活动的有效时间引入知识的积累方程———“点子”生产函数,发现OECD国家科学家和工程师数量增加伴随着R&D人员创新活动的有效时间的减少,二者相互抵消,使得TFP增长率保持不变。通过校准理论模型,本文模拟了49个国家的经济增长率,发现模型对经济增长率跨国数据的解释能力明显强于Lucas模型和Romer模型。如果利用模型对跨国经济增长率的模拟值与真实值之间的残差平方和来评判模型的优劣,则本文模型对Lucas模型和Romer模型至少分别改进了20%和59%。     

Structural Change,Urban Congestion,and the End of Growth

This paper develops a two‐sector R&D‐based growth model with congestion effects from increasing urban population density. We show that endogenous technological progress causes structural change if there are positive productivity spillovers from the modern to the traditional sector and Engel's law holds. In turn, urban congestion effects cause a productivity slowdown in the modern sector. Eventually, economic growth may cease in the long‐run. We also show that land dilution by a larger workforce may give rise to negative scale effects on (GDP) per capita.     

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。     

Demographic change,human capital accumulation and R&D‐based growth

Employing an overlapping generations model of R&D‐based growth with endogenous fertility and education decisions, we examine how demographic changes induced by an increase in life expectancy influence the long‐run growth rate of the economy. We demonstrate that life expectancy, when relatively low (high), positively (negatively) affects economic growth. This paper also compares the growth implications of child education subsidy policies (i.e., policies for enhancing basic education) and child rearing subsidy policies (i.e., pro‐natal policies) and demonstrate that while the child education subsidies consistently foster economic growth, child rearing subsidies may negatively affect economic growth.     

基于分工和报酬递增的经济增长理论演进

文章对分工、报酬递增和经济增长相关理论的演进进行了梳理和总结.古典经济增长理论奠定了思想基础.其中,斯密理论是通过拓展新的分工实现内生和自我持续增长理论的基础;马克思关于分工形式的划分推进了对于报酬递增机制的认识;杨格开创了分工、报酬递增和经济增长的动态分析思路.内生增长理论以技术进步、知识资本和人力资本积累促进经济增长为核心,将分工和技术进步、知识积累紧密联系起来,以分工为重要分析框架论证报酬递增和长期经济增长的实现,吸收和发展了分工理论.内生增长理论和相关模型分别依循由古典经济学开创的两种分工观进行分析,对分工、报酬递增和经济 增长的相关理论和模型进行了重要扩展和充实.     

NON‐UNIFORM STRATEGIC TRADE POLICY AND AGGREGATE PROFIT CREATION EFFECT

This paper illustrates a new theoretical case for a strategic R&D policy in a two‐country third‐market international oligopoly model. Asymmetric treatment of domestic firms through a non‐uniform R&D policy can create aggregate profits without a foreign retaliation concern and further improve national welfare in addition to what a uniform policy accomplishes. This effect occurs when the conventional Brander–Spencer incentive is entirely absent as well as when the uniformly optimal R&D policy initially prevailed. The superiority of non‐uniform policy to uniform‐policy is not guaranteed, however, when the number of firms becomes endogenous.     

Technological opportunity and the growth of knowledge: A Schumpeterian approach to measurement

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.     

On the Growth and Welfare Effects of Defense R&D

In the United States, defense R&D share of GDP has decreased significantly since 1960. To analyze the implications on growth and welfare, we develop an R&D‐based growth model that features the commonly discussed crowding‐out and spillover effects of defense R&D on civilian R&D. The model also captures the effects of defense technology on (a) national security resembling consumption‐type public goods and (b) aggregate productivity via the spin‐off effect resembling productive public goods. In this framework, economic growth is driven by market‐based civilian R&D as in standard R&D‐based growth models and government‐financed public goods (i.e., defense R&D) as in Barro (1990). We find that defense R&D has an inverted‐U effect on growth, and the growth‐maximizing level of defense R&D is increasing in the spillover and spin‐off effects. As for the welfare‐maximizing level of defense R&D, it is increasing in the security‐enhancing effect of defense technology, and there exists a critical degree of this security‐enhancing effect below (above) which the welfare‐maximizing level is below (above) the growth‐maximizing level.     

Patent claims and economic growth

This study introduces a blocking patent on horizontal R&D into the endogenous growth model of Chu et al. (2012), which features a blocking patent on vertical R&D. Results show that strengthening patent protection on horizontal R&D promotes vertical innovation (quality improvement) but hinders horizontal innovation (variety expansion). This effect of a horizontal blocking patent on directionality of innovation is opposite to that of the vertical blocking patent analyzed by Chu et al. (2012). Results also show that under mild conditions, strengthening a blocking patent on horizontal innovation as well as on vertical innovation can increase economic growth and social welfare.     

Channels of transmission of environmental policy to economic growth: A survey of the theory

Economists generally hold that environmental regulations impose constraints on the production possibilities set and are therefore potentially harmful to economic growth. In recent years, however, it has been recognized that environmental regulation can enhance the prospects for growth if improved environmental quality increases the productivity of inputs or the efficiency of the education system. It is also held that environmental regulation promotes pollution abatement activity and can lead to the exploitation of increasing returns to scale in abatement. Furthermore, expectations of a better environment may encourage households to save. Finally, it has been conjectured that environmental regulations can stimulate innovation because R&D is a relatively clean activity and because the market share of clean innovations increases. Future empirical research should shed light on the relative importance of these different channels of transmission of environmental policy to the growth rate of the economy.     

Technological complexity and economic growth

Over the last fifty years there have been large secular increases in educational attainment and R&D intensity. The fact that these trends have not stimulated more rapid income growth has been a persistent puzzle for growth theorists. We construct a model of endogenous economic growth in which income growth, R&D intensity, and educational attainment depend on the complexity of new technologies. An increase in complexity that makes passive learning more difficult induces increases in R&D and education, alongside a decline in income growth. Our explanation also predicts a concurrent rise in the skill premium.