903 resultados para Growth Model
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This paper introduces a model economy in which formation of coalition groups under technological progress is generated endogenously. The coalition formation depends crucially on the rate of arrival of new technologies. In the model, an agent working in the saroe technology for more than one period acquires skills, part of which is specific to this technology. These skills increase the agent productivity. In this case, if he has worked more than one period with the same technology he has incentives to construct a coalition to block the adoption of new technologies. Therefore, in every sector the workers have incentives to construct a coalition and to block the adoption of new technologies. They will block every time that a technology stay in use for more than one period.
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This article studies the interplay between fiscal rules, public investment and growth in Brazil. It is investigated if it would make sense to raise public investment and, if so, under which fiscal rule it is best to do it — whether through tax financing, debt financing, or a reduction of public consumption. We construct and simulate a competitive general equilibrium model, calibrated to Brazilian economy, in which public capital is a component of the production function and public consumption directly affects individuals’ well-being. After assessing the impacts of alternative fiscal rules, the paper concludes that the most desirable financing scheme is the reduction of public consumption, which dominates the others in terms of output and welfare gains. The model replicates the observed growth slowdown of the Brazilian economy when we increase taxes and reduce public capital formation to the levels observed after 1980 and shows that the growth impact of the expansion of tax collection in Brazil was much larger than that of public investment compression.
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We assess the effects of the imperfect substitution between skilled and unskilled labor on economic growth in a model in which physical capital and skilled labor can be accumulated. It is shown that economies with higher substitutability between skilled and unskilled labor have higher levels of income per capita in the transition and in the long-run equilibrium. Furthermore, these economies have a higher level of skilled labor and a higher level of capital intensity in the long-run equilibrium. For certain parameters values, the speed of convergence depends positively on the elasticity of substitution between skilled and unskilled labor.
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In spite of Latin America s dismal economic performance between the 1950s and 1980s, the region experienced strong capital deepening. Furthermore, pro- ductivity (measured as TFP) grew at low rates in comparison with the U.S. In this paper, we suggest that all these facts can be explained as a consequence of the restrictive trade regime adopted at that time. Our analytical framework is based on a dynamic Heckscher-Ohlin model, with scale economies in the capital- intensive sector. We assume an economy that is initially open and specialized in the production of labor-intensive goods. The trade regime is modeled as a move to a closed economy. The model produces results consistent with the Latin American experience. Speci cally, for a su¢ ciently small country, there will be no long-run growth in income per capita, but capital per capita will increase. As a result, measured TFP will fall.
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A fundamental question in development economics is why some economies are rich and others poor. To illustrate the income per capita gap across economies consider that the average gross domestic product (GDP) per capita of the richest 10 percent of economies in the year 2010 was a factor of 40-fold that of the poorest 10 percent of economies. In other words, the average person in a rich economy produces in just over 9 days what the average person in a poor economy produces in an entire year. What are the factors that can explain this difference in standard of living across the world today? With this in view, this dissertation is a conjunction of three essays on the economic growth field which we seek a possible responses to this question. The first essay investigates the existence of resource misallocation in the Brazilian manufacturing sector and measures possible distortions in it. Using a similar method of measurement to the one developed by Hsieh and Klenow (2009) and firm-level data for 1996-2011 we find evidence of misallocation in the manufacturing sector during the observed period. Moreover, our results show that misallocation has been growing since 2005, and it presents a non-smooth dynamic. Significantly, we find that the Brazilian manufacturing sector operates at about 50% of its efficient product. With this, if capital and labor were optimally reallocated between firms and sectors we would obtain an aggregate output growth of approximately 110-180% depending on the mode in which the capital share is measured. We also find that the economic crisis did not have a substantial effect on the total productivity factor or on the sector's misallocation. However, small firms in particular seem to be strongly affected in a global crisis. Furthermore, the effects described would be attenuated if we consider linkages and complementarity effects among sectors. Despite Brazil's well-known high tax burden, there is not evidence that this is the main source of resource misallocation. Moreover, there is a distinct pattern of structural change between the manufacturing sectors in industrialized countries and those in developing countries. Therefore, the second essay demonstrate that this pattern differs because there are some factors that distort the relative prices and also affect the output productivity. For this, we present a multi-sector model of economic growth, where distortions affect the relative prices and the allocation of inputs. This phenomenon imply that change of the production structure or perpetuation of the harmful structures to the growth rate of aggregate output. We also demonstrate that in an environment with majority decision, this distortion can be enhanced and depends on the initial distribution of firms. Furthermore, distortions in relative prices would lead to increases in the degree of misallocation of resources, and that imply that there are distinct patterns of structural changes between economies. Finally, the calibrated results of the framework developed here converge with the structural change observed in the firm-level data of the Brazilian manufacturing sector. Thereafter, using a cross-industry cross-country approach, the third essay investigates the existence of an optimal level of competition to enhance economic growth. With that in mind, we try to show that this optimal level is different from industrialized and under development economies due to the technology frontier distance, the terms of trade, and each economy's idiosyncratic characteristics. Therefore, the difference in competition industry-country level is a channel to explain the output for worker gap between countries. The theoretical and empirical results imply the existence of an inverted-U relationship between competition and growth: starting for an initially low level of competition, higher competition stimulates innovation and output growth; starting from a high initial level of competition, higher competition has a negative effect on innovation and output growth. Given on average industries in industrialized economies present higher competition level. With that if we control for the terms of trade and the industry-country fixed effect, if the industries of the developing economy operated under the same competition levels as of the industrialized ones, there is a potential increase of output of 0.2-1.0% per year. This effect on the output growth rate depends on the competition measurement used.
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This dissertation surveys the literature on economic growth. I review a substantial number of articles published by some of the most renowned researchers engaged in the study of economic growth. The literature is so vast that before undertaking new studies it is very important to know what has been done in the field. The dissertation has six chapters. In Chapter 1, I introduce the reader to the topic of economic growth. In Chapter 2, I present the Solow model and other contributions to the exogenous growth theory proposed in the literature. I also briefly discuss the endogenous approach to growth. In Chapter 3, I summarize the variety of econometric problems that affect the cross-country regressions. The factors that contribute to economic growth are highlighted and the validity of the empirical results is discussed. In Chapter 4, the existence of convergence, whether conditional or not, is analyzed. The literature using both cross-sectional and panel data is reviewed. An analysis on the topic of convergence using a quantile-regression framework is also provided. In Chapter 5, the controversial relationship between financial development and economic growth is analyzed. Particularly, I discuss the arguments in favour and against the Schumpeterian view that considers financial development as an important determinant of innovation and economic growth. Chapter 6 concludes the dissertation. Summing up, the literature appears to be not fully conclusive about the main determinants of economic growth, the existence of convergence and the impact of finance on growth.
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A total of 2629 individuals of Arenaeus cribrarius (1293 males and 1336 females) were captured in Ubatuba (SP), from August 1996 to July 1997. Individuals were distributed in 5 mm size class carapace width (CW), to verify sex-specific growth-age equations. The Von Bertalanffy model was chosen to determine the growth rate and expressed by CW=120.52[1-e(-1.80t)] for males and CW=100.81[1-e(-1.60t)] for females. The age estimated for the first juvenile stage (t(o)) was 6.1 and 8.3 days for males and females, respectively. The maximum age determined was 1.8 years for males and 2 years for females, which correspond to a maximum size of 115.8 and 96.7 mm, respectively. The maximum size (CWmax) estimated using 95% of asymptotic size was 114.5 mm for males and 95.8 mm for females. Males have a precocious sexual maturity (5 months) when compared to females (6.8 months). The growth rate and size of A. cribrarius are higher than other portunid species, with great interest for aquaculture.
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Temporally-growing frontal meandering and occasional eddy-shedding is observed in the Brazil Current (BC) as it flows adjacent to the Brazilian Coast. No study of the dynamics of this phenomenon has been conducted to date in the region between 22 degrees S and 25 degrees S. Within this latitude range, the flow over the intermediate continental slope is marked by a current inversion at a depth that is associated with the Intermediate Western Boundary Current (IWBC). A time series analysis of 10-current-meter mooring data was used to describe a mean vertical profile for the BC-IWBC jet and a typical meander vertical structure. The latter was obtained by an empirical orthogonal function (EOF) analysis that showed a single mode explaining 82% of the total variance. This mode structure decayed sharply with depth, revealing that the meandering is much more vigorous within the BC domain than it is in the IWBC region. As the spectral analysis of the mode amplitude time series revealed no significant periods, we searched for dominant wavelengths. This search was done via a spatial EOF analysis on 51 thermal front patterns derived from digitized AVHRR images. Four modes were statistically significant at the 95% confidence level. Modes 3 and 4, which together explained 18% of the total variance, are associated with 266 and 338-km vorticity waves, respectively. With this new information derived from the data, the [Johns, W.E., 1988. One-dimensional baroclinically unstable waves on the Gulf Stream potential vorticity gradient near Cape Hatteras. Dyn. Atmos. Oceans 11, 323-350] one-dimensional quasi-geostrophic model was applied to the interpolated mean BC-IWBC jet. The results indicated that the BC system is indeed baroclinically unstable and that the wavelengths depicted in the thermal front analysis are associated with the most unstable waves produced by the model. Growth rates were about 0.06 (0.05) days(-1) for the 266-km (338-km) wave. Moreover, phase speeds for these waves were low compared to the surface BC velocity and may account for remarks in the literature about growing standing or stationary meanders off southeast Brazil. The theoretical vertical structure modes associated with these waves resembled very closely to the one obtained for the current-meter mooring EOF analysis. We interpret this agreement as a confirmation that baroclinic instability is an important mechanism in meander growth in the BC system. (C) 2008 Elsevier B.V. All rights reserved.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The total meat yield in a beef cattle production cycle is economically very important and depends on the number of calves born per year or birth season, being directly related to reproductive potential. Accumulated Productivity (ACP) is an index that expresses a cow's capacity to give birth regularly at a young age and to wean animals of greater body weight. Using data from cattle participating in the "Program for Genetic Improvement of the Nelore Breed" (PMGRN - Nelore Brasil), bi-trait analyses were performed using the Restricted Maximum Likelihood method based on an ACP animal model and the following traits: age at first calving (AFC), female body weight adjusted for 365 (BW365) and 450 (BW450) days of age, and male scrotal circumference adjusted for 365 (SC365), 450 (SC450), 550 (SC550) and 730 (SC730) days of age. Median estimated ACP heritability was 0.19 and the genetic correlations with AFC, BW365, BW450, SC365, SC450, SC550 and SC730 were 0.33, 0.70, 0.65, 0.08, 0.07, 0.12 and 0.16, respectively. ACP increased and AFC decreased over time, revealing that the selection criteria genetically improved these traits. Selection based on ACP appears to favor the heaviest females at 365 and 450 days of age who showed better reproductive performance as regards AFC. Scrotal circumference was not genetically associated with ACP. (C) 2007 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Introduction. Leaf area is often related to plant growth, development, physiology and yield. Many non-destructive models have been proposed for leaf area estimation of several plant genotypes, demonstrating that leaf length, leaf width and leaf area are closely correlated. Thus, the objective of our study was to develop a reliable model for leaf area estimation from linear measurements of leaf dimensions for citrus genotypes. Materials and methods. Leaves of citrus genotypes were harvested, and their dimensions (length, width and area) were measured. Values of leaf area were regressed against length, width, the square of length, the square of width and the product (length x width). The most accurate equations, either linear or second-order polynomial, were regressed again with a new data set; then the most reliable equation was defined. Results and discussion. The first analysis showed that the variables length, width and the square of length gave better results in second-order polynomial equations, while the linear equations were more suitable and accurate when the width and the product (length x width) were used. When these equations were regressed with the new data set, the coefficient of determination (R(2)) and the agreement index 'd' were higher for the one that used the variable product (length x width), while the Mean Absolute Percentage Error was lower. Conclusion. The product of the simple leaf dimensions (length x width) can provide a reliable and simple non-destructive model for leaf area estimation across citrus genotypes.
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Xylella fastidiosa is the etiologic agent of diseases in a wide range of economically important crops including citrus variegated chlorosis, a major threat to the Brazilian citrus industry. The genomes of several strains of this phytopathogen have been completely sequenced enabling large-scale functional studies. In this work we used whole-genome DNA microarrays to investigate the transcription profile of X. fastidiosa grown in defined media with different glucose concentrations. Our analysis revealed that while transcripts related to fastidian gum production were unaffected, colicin-V-like and fimbria precursors were induced in high glucose medium. Based on these results, we suggest a model for colicin-defense mechanism in X. fastidiosa.
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Growth curves models provide a visual assessment of growth as a function of time, and prediction body weight at a specific age. This study aimed at estimating tinamous growth curve using different models, and at verifying their goodness of fit. A total number 11,639 weight records from 411 birds, being 6,671 from females and 3,095 from males, was analyzed. The highest estimates of a parameter were obtained using Brody (BD), von Bertalanffy (VB), Gompertz (GP,) and Logistic function (LG). Adult females were 5.7% heavier than males. The highest estimates of b parameter were obtained in the LG, GP, BID, and VB models. The estimated k parameter values in decreasing order were obtained in LG, GP, VB, and BID models. The correlation between the parameters a and k showed heavier birds are less precocious than the lighter. The estimates of intercept, linear regression coefficient, quadratic regression coefficient, and differences between quadratic coefficient of functions and estimated ties of quadratic-quadratic-quadratic segmented polynomials (QQQSP) were: 31.1732 +/- 2.41339; 3.07898 +/- 0.13287; 0.02689 +/- 0.00152; -0.05566 +/- 0.00193; 0.02349 +/- 0.00107, and 57 and 145 days, respectively. The estimated predicted mean error values (PME) of VB, GP, BID, LG, and QQQSP models were, respectively, 0.8353; 0.01715; -0.6939; -2.2453; and -0.7544%. The coefficient of determination (RI) and least square error values (MS) showed similar results. In conclusion, the VB and the QQQSP models adequately described tinamous growth. The best model to describe tinamous growth was the Gompertz model, because it presented the highest R-2 values, easiness of convergence, lower PME, and the easiness of parameter biological interpretation.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)