Complementarities, Costly Investment and Multiple Equilibria in a One-Sector Endogenous Growth Model

In this paper we develop a multiple equilibria one-sector R&D-based growth model, in which the key aspects are the assumption of complementarities between capital goods in the production function and the assumption of costly investment in capital. This second assumption is new to the R&D-based literature. The equilibrium solutions are obtained when the Preferences curve, which mirrors consumers’ savings decisions, and the Technology curve, which represents equilibria on the production side, cross. The combination of the two key assumptions produces a non-linear Technology curve, which consequently crosses the Preferences curve more than once, thus generating multiple equilibria. A numerical solutions exercise obtains two equilibria. Application of the stability under learning criterion allows for the identification of the two equilibria as stable. Expectations can lead the economy to either the equilibrium characterised by high-growth and high-interest rates, or to the equilibrium characterised by low-growth and low-interest rates. Hence, with this model, we wish to contribute to endogenous growth literature by providing a mechanism to explain how an economy can experience multiple equilibria situations.Growth, R&D, complementarities, costly investment, multiple equilibria.

A Nonscale Growth Model with R&D and Human Capital Accumulation

This paper presents an endogenous growth model that includes research and development and human capital accumulation. The model’s specification builds on the R&D-based structure of Romer’s [1990] model and introduces two functions: (1) A specification for the production of new designs that assumes no externalities and no inventions before time zero; and (2) A specification for the accumulation of human capital technically similar to that in Lucas [1988]. The model displays two main results. The first is that it eliminates the scale-effects prediction which is common to most R&D-based growth models, but which is not empirically supported. Secondly, the model offers a new prediction that growth depends positively on the ratio of final-good workers to researchers. Thus the model provides a theoretical explanation as to why developed countries have had rising numbers of researchers but not rising growth rates in the twentieth century.endogenous growth; research and development; human capital accumulation; scale-effects prediction; final-good workers to researchers ratio.

Complementarities, costly investment and multiple equilibria in a one-sector endogenous growth model

In this paper we develop a multiple equilibria one-sector R&D-based growth model, in which the key aspects are the assumption of complementarities between capital goods in the production function and the assumption of costly investment in capital. This second assumption is new to the R&D-based literature. The equilibrium solutions are obtained when the Preferences curve, which mirrors consumers’ savings decisions, and the Technology curve, which represents equilibria on the production side, cross. The combination of the two key assumptions produces a non-linear Technology curve, which consequently crosses the Preferences curve more than once, thus generating multiple equilibria. A numerical solutions exercise obtains two equilibria. Application of the stability under learning criterion allows for the identification of the two equilibria as stable. Expectations can lead the economy to either the equilibrium characterised by high-growth and high-interest rates, or to the equilibrium characterised by low-growth and low-interest rates. Hence, with this model, we wish to contribute to endogenous growth literature by providing a mechanism to explain how an economy can experience multiple equilibria situations

A Nonscale growth model with R&D and human capital accumulation

This paper presents an endogenous growth model that includes research and development and human capital accumulation. The model’s specification builds on the R&D-based structure of Romer’s [1990] model and introduces two functions: (1) A specification for the production of new designs that assumes no externalities and no inventions before time zero; and (2) A specification for the accumulation of human capital technically similar to that in Lucas [1988]. The model displays two main results. The first is that it eliminates the scale-effects prediction which is common to most R&D-based growth models, but which is not empirically supported. Secondly, the model offers a new prediction that growth depends positively on the ratio of final-good workers to researchers. Thus the model provides a theoretical explanation as to why developed countries have had rising numbers of researchers but not rising growth rates in the twentieth century.Fundação para a Ciência e Tecnologia - (FCT)

Social capital, innovation and economic growth

Multidisciplinary innovation is the engine of growth of an increasing number of economies. Innovation output depends increasingly on information sharing and cooperation between creative agents. Sharing and cooperation requires the existence of generalised trust. Social capital consists of trust and trust-based networks. Our main goal is to illustrate theoretically the importance of social capital to the growth of an innovation economy.COMPETE, QREN, FEDER, Fundação para a Ciência e a Tecnologia (FCT

A Growth Model for the Quadruple Helix Innovation Theory

We propose a theoretical growth model with which to frame analytically the Quadruple Helix Innovation Theory (QHIT). The aim is to emphasise the investment in innovation transmission mechanisms in terms of economic growth and productivity gains, in one-high-technology sector, by stressing the role played by the helices of the Quadruple Helix Innovation Model: Academiaand Technological Infrastructures, Firms of Innovation, Government and Civil Society. In the existing literature, the relationship between the helices and respective impacts on economic growth does not appear clear. Results are fragiledue to data weakness and the inexistence of a theoretical framework to specify the relationship between the helices. Hence our motivation for providing the QHIT with a theoretical growth model. Our intent is to model the importance of emerging, dynamically adaptive, and transdisciplinary knowledge and innovation ecosystems to economic growth. We .nd that higher economic growth rate is obtained as a result of an increase in synergies and complementarities between different productive units, or an incease in productive government expenditure.Economic Growth; Quadruple Helix Innovation Model; Innovation Ecosystems.

Innovation economy, productive public expenditures and economic growth

Innovation is the main engine of growth in an increasing number of economies. Innovation economies are, according to the Quadruple Helix (QH) Innovation Theory, sustained by four pilars – Firms, Academia, Government and Consumers –, all operating in a systemic, interactive environment. We provide a model that gives analytical body to the QH theory and links formally innovation to economic growth. We aim to emphasise the equally important roles of the four helices sustaining an innovation economy and its long run growth. In particular, given the downwards pressure on Government expenditures, we analyse the effects of an increase in public expenditures on economic growth, which we find positive in the short, medium and long-run.COMPETE; QREN; FEDER; Fundação para a Ciência e a Tecnologia (FCT

A growth model for the quadruple helix innovation theory

We propose a theoretical growth model with which to frame analytically the Quadruple Helix Innovation Theory (QHIT). The aim is to emphasise the investment in innovation transmission mechanisms in terms of economic growth and productivity gains, in one-high-technology sector, by stressing the role played by the helices of the Quadruple Helix Innovation Model: Academiaand Technological Infrastructures, Firms of Innovation, Government and Civil Society. In the existing literature, the relationship between the helices and respective impacts on economic growth does not appear clear. Results are fragiledue to data weakness and the inexistence of a theoretical framework to specify the relationship between the helices. Hence our motivation for providing the QHIT with a theoretical growth model. Our intent is to model the importance of emerging, dynamically adaptive, and transdisciplinary knowledge and innovation ecosystems to economic growth. We .nd that higher economic growth rate is obtained as a result of an increase in synergies and complementarities between different productive units, or an incease in productive government expenditure.Fundação para a Ciência e a Tecnologia (FCT

Frequency and genotypic distribution of GB virus C (GBV-C) among Colombian population with Hepatitis B (HBV) or Hepatitis C (HCV) infection

<p>Abstract</p> <p>Background</p> <p>GB virus C (GBV-C) is an enveloped positive-sense ssRNA virus belonging to the <it>Flaviviridae </it>family. Studies on the genetic variability of the GBV-C reveals the existence of six genotypes: genotype 1 predominates in West Africa, genotype 2 in Europe and America, genotype 3 in Asia, genotype 4 in Southwest Asia, genotype 5 in South Africa and genotype 6 in Indonesia. The aim of this study was to determine the frequency and genotypic distribution of GBV-C in the Colombian population.</p> <p>Methods</p> <p>Two groups were analyzed: i) 408 Colombian blood donors infected with HCV (n = 250) and HBV (n = 158) from Bogotá and ii) 99 indigenous people with HBV infection from Leticia, Amazonas. A fragment of 344 bp from the 5' untranslated region (5' UTR) was amplified by nested RT PCR. Viral sequences were genotyped by phylogenetic analysis using reference sequences from each genotype obtained from GenBank (n = 160). Bayesian phylogenetic analyses were conducted using Markov chain Monte Carlo (MCMC) approach to obtain the MCC tree using BEAST v.1.5.3.</p> <p>Results</p> <p>Among blood donors, from 158 HBsAg positive samples, eight 5.06% (n = 8) were positive for GBV-C and from 250 anti-HCV positive samples, 3.2%(n = 8) were positive for GBV-C. Also, 7.7% (n = 7) GBV-C positive samples were found among indigenous people from Leticia. A phylogenetic analysis revealed the presence of the following GBV-C genotypes among blood donors: 2a (41.6%), 1 (33.3%), 3 (16.6%) and 2b (8.3%). All genotype 1 sequences were found in co-infection with HBV and 4/5 sequences genotype 2a were found in co-infection with HCV. All sequences from indigenous people from Leticia were classified as genotype 3. The presence of GBV-C infection was not correlated with the sex (p = 0.43), age (p = 0.38) or origin (p = 0.17).</p> <p>Conclusions</p> <p>It was found a high frequency of GBV-C genotype 1 and 2 in blood donors. The presence of genotype 3 in indigenous population was previously reported from Santa Marta region in Colombia and in native people from Venezuela and Bolivia. This fact may be correlated to the ancient movements of Asian people to South America a long time ago.</p