5,016 research outputs found
A simple bivariate count data regression model
This paper develops a simple bivariate count data regression model in which dependence between count variables is introduced by means of stochastically related unobserved heterogeneity components. Unlike existing commonly used bivariate models, we obtain a computationally simple closed form of the model with an unrestricted correlation pattern.
Tobacco Chewing, Smoking and Health Knowledge: Evidence from Bangladesh
Unlike the substance abuse studies in developed countries, tobacco consumption and its adverse effects in developing countries are poorly studied. The objective of this paper is to identify which factors influence individuals' decision to smoke cigarettes, chew tobacco and their knowledge about the health hazards of tobacco use. To allow for the potential correlation among smoking tobacco, chewing tobacco, and health knowledge, we estimate a trivariate probit regression model using household survey data from Bangladesh. For both chewing tobacco and smoking, the results show how the probabilities of uninformed tobacco user and uninformed nonuser vary across different demographic groups.Chewing tobacco
Keeping an eye on decentralization and specification of a resource policy: An overview of the policy study to the promotion of RWH
Water policyRainWater harvestingSoil conservationIrrigation waterWater rights
Flow boiling in a 1.1mm tube with R134a: Experimental results and comparison with model
A detailed comparison of the three-zone evaporation model, proposed by Thome et al. (2004), with experimental heat transfer results of two stainless steel tubes of internal diameter 4.26 mm and 2.01 mm using R134a fluid was presented by Shiferaw et al. (2006). In the current paper the comparison is extended to flow boiling in a 1.1 mm tube using R134a as the working fluid. Other parameters were varied in the range: mass flux 100-600 kg/m2.s; heat flux 16-150 kW/m2 and pressure 6-12 bar.
The experimental results demonstrate that the heat transfer coefficient increases with heat flux and system pressure, but does not change with vapour quality when the quality is less than about 50% for low heat and mass flux values. The effect of mass flux is observed to be insignificant. For vapour quality values greater than 50% and at high heat flux values, the heat transfer coefficient does not depend on heat flux and decreases with vapour quality. This could be caused by partial dryout. The three-zone evaporation model predicts the experimental results fairly well, especially at relatively low pressure. However, the partial dryout region is highly over-predicted by the model. The sensitivity of the performance of the model to the three optimized parameters (confined bubble frequency, initial film thickness and end film thickness) and some preliminary investigation relating the critical film thickness for dryout to measured tube roughness are also discussed
Decomposing the education wage gap: everything but the kitchen sink
This paper contributes to a large literature concerned with identifying the source of the widening wage gap between high school and college graduates by providing a comprehensive, multidimensional decomposition of wages across both time and educational status. Data from a multitude of sources are brought to bear on the question of the relative importance of labor market supply and demand factors in the determination of those wage differences. The results confirm the importance of investments in and use of technology, which has been the focus of most of the previous literature, but are also able to show that demand and supply factors played very different roles in the growing wage gaps of the 1980s and 1990s.
Decomposing the education wage gap: everything but the kitchen sink
The authors use a multitude of data sources to provide a comprehensive, multidimensional decomposition of wages across both time and educational status. Their results confirm the importance of investments in and use of technology, which has been the focus of most of the previous literature. The authors also show that demand and supply factors played very different roles in the growing wage gaps of the 1980s and 1990s.Education - Economic aspects ; Wages ; Education
PATENTS, R&D AND LAG EFFECTS: EVIDENCE FROM FLEXIBLE METHODS FOR COUNT PANEL DATA ON MANUFACTURING FIRMS
Hausman, Hall and Griliches (1984) and Hall, Griliches and Hausman (1986) investigated whether there was a lag in the patent-R&D relationship for the U.S. manufacturing sector using 1970¿s data. They found that there was little evidence of anything but contemporaneous movement of patents and R&D. We reexamine this important issue employing new longitudinal patent data at the firm level for the U.S. manufacturing sector from 1982 to 1992. To address unique features of the data, we estimate various distributed lag and dynamic multiplicative panel count data models. The paper also develops a new class of count panel data models based on series expansion of the distribution of individual effects. The empirical analyses show that, although results are somewhat sensitive to different estimation methods, the contemporaneous relationship between patenting and R&D expenditures continues to be rather strong, accounting for over 60% of the total R&D elasticity. Regarding the lag structure of the patents-R&D relationship, we do find a significant lag in all empirical specifications. Moreover, the estimated lag effects are higher than have previously been found, suggesting that the contribution of R&D history to current patenting has increased from the 1970¿s to the 1980¿s.Innovative activity, Patents and R&D, Individual effects, count panel data methods.
The Japanese Market for Imported Fruit Juices
The objectives were to analyze the competitiveness of countries exporting fruit juices into Japan and simulate the effect of the negative Japanese population growth rate on fruit juice demand. The relative price version of the Rotterdam demand model was estimated for orange, grapefruit, other citrus, apple, pineapple and grape juices. Results indicate that most exporters can’t increase market share through price reductions. Product promotion and product differentiation is a more plausible option. The growth of fruit juice demand in Japan is expected to decrease over the period 2006 through 2020 for 11 of the 18 fruit juice/country combinations because of negative population growth rate.competitiveness, fruit juice, Japan, Rotterdam model, population decline, Agribusiness, Agricultural and Food Policy, International Development, Q1,
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