The Economic Efficiency of Policy Reform and Partial Market Liberalization under Transaction Costs

The article presents an integrated analysis of the effects of domestic and trade policy reform on resource allocation and welfare under transaction costs. It develops a general multiagent, multicommodity model, where transaction costs are the costs of resources used in the exchange process. The influence of domestic and trade policy (including both price and quantity instruments) on distorted market equilibrium is analysed. Alternative concepts of distorted equilibrium are presented and investigated. They provide a basis for evaluating the effects of multilateral partial market liberalization on resource allocation and welfare under transaction costs. New conditions are derived under which multilateral policy reforms generate Pareto improvements.     

On the Use of Price Ratio in Aggregate Supply Response: Some Evidence from the Poultry Industry

The specification of supply/demand relationships has received considerable attention in agricultural economics (Heien 1977). Economic theory has helped provide a basis for the specification of such relationships, one of its contributions being the proposition that prices should be interpreted only in relative terms. This has had a profound influence on model building in agricultural economics, leading a number of researchers to avoid the use of absolute prices in economic analysis. For this reason, numerous market models of the agricultural economy use price ratios as explanatory variables (e.g., Chen; Chen et al.; Heien, 1976; Gerra; Kulshreshtha and Wilson; Rahn; Talpaz; Morzuck et al.; Houck and Gallagher; Wilson et al.); these examples suggest that the use of such ratios is fairly widespread in econometric modeling of the crop and livestock sectors. One of the best examples of price ratios is the "feed cost to price" ratio commonly used in the analysis of livestock supply response. Indeed, since feed cost constitutes a major part of the total production cost in livestock activities, the "feed cost to price" ratio is often considered a proxy for profitability. For this reason, data on such ratios are regularly published for various livestock activities (e.g., USD A). Also, "feed cost to price" ratios are often employed in the specification of models of livestock supply response, (e.g., Chen; Chen et al.; Heien 1976; Gerra; Kulshreshtha and Wilson; Rahn; Talpaz). However, not all models of aggregate supply response follow this approach. For example, Freebairn and Rausser, and Arzac and Wilkinson, use prices as separate variables rather than in ratio forms in their models. In particular, they do not employ price ratios in their livestock and crop supply equations. The existence of these different approaches raises questions about the appropriateness of the use of price ratios in the modeling of aggregate supply.     

The microeconomics of food security

This article develops a dynamic microeconomic model of food security under uncertainty, with special focus on the relationships between food demand, nutrition and human survival. It investigates the influence of entitlements on malnutrition, hunger and starvation under uncertainty. It develops useful insights on the links between food security and a number of policy instruments commonly used in dealing with malnutrition and starvation.     

On Crop Biodiversity, Risk Exposure, and Food Security in the Highlands of Ethiopia

This paper investigates the effects of crop genetic diversity on farm productivity and production risk in the highlands of Ethiopia. Using a moment-based approach, the analysis uses a stochastic production function capturing mean, variance, and skewness effects. Welfare implications of diversity are evaluated using a certainty equivalent, measured as expected income minus a risk premium (reflecting the cost of risk). We find that the effect of diversity on skewness dominates its effect on variance, meaning that diversity reduces the cost of risk. The analysis also shows that the beneficial effects of diversity become of greater value in degraded land.     

Price Dynamics in a Vertical Sector: The Case of Butter

We develop a reduced-form model of price transmission in a vertical sector, allowing for refined asymmetric, contemporaneous and lagged, own and cross-price effects under time-varying volatility. The model is used to investigate the wholesale-retail price dynamics in the U.S. butter market. The analysis documents the nature of nonlinear price dynamics in a vertical sector. It finds strong evidence of asymmetric retail price responses, both in the short term and the longer term, but only weak evidence of asymmetric wholesale price responses. Asymmetric retail responses play a major role in generating a skewed distribution of butter prices. The empirical results indicate the presence of imperfect competition at the retail level.     

Crop genetic diversity, farm productivity and the management of environmental risk in rainfed agriculture

This paper presents an assessment of the linkages between cropgenetic diversity, farm productivity and risk management. Aflexible moment-based approach is used to analyse the impactof crop genetic diversity on the mean, variance and skewnessof yield. Using farm-level data from Sicily (Italy), econometricevidence shows how crop genetic diversity can increase farmproductivity and reduce risk exposure. The empirical resultsindicate that crop genetic diversity can reduce variance, butonly if pesticide use is low. Furthermore, high diversity levelscan reduce downside risk exposure (e.g. the risk of crop failure).This provides useful insights on the linkages between resilienceand crop genetic diversity.     

A Heteroskedastic Multivariate Tobit Analysis of Price Dynamics in the Presence of Price Floors

This article presents an econometric analysis of the effects of price floors on price dynamics and price volatility in a multimarket context. We investigate the implications of a government price-support program providing a censoring mechanism to the price determination process. The analysis uses a dynamic multivariate Tobit model under time-varying volatility. The model is applied to the U.S. dairy markets with a special focus on the effects of government price-support programs in a period of market liberalization. The econometric analysis provides useful information on the multimarket effects of price supports on price dynamics and price volatility.     

不断推进中国特色社会主义新发展

只有社会主义才能救中国、发展中国,这是中国近现代史和中国革命实践得出的正确结论.中国新民主主义革命的胜利和中华人民共和国的建立,为社会主义制度在中国的确立奠定了基础.