Cap towards 2020 and the cost of political choices: The case of Emilia-romagna region

The paper assesses the different schemes of regionalisation and greening implementation according to both the preliminary proposals presented to the Trilogue and the CAP Reform adopted on 16 December 2013. The objective is to compare the different potential impacts on production (land use) and on the economic revenue of farm holders in the Emilia-Romagna region (Italy). The assessment is performed by a regional positive mathematical programming (PMP) model and is carried out for single farms appearing in the Farm Accountancy Data Network (FADN) data. Sampling weights are used to make the simulation results consistent with the production structure of the region. The findings confirm a big weakening in what would have been the impact of the Commission’s proposal. In terms of lower gross margin incurred by farmers for fulfilling the greening requirements in the final CAP scenario, the model estimates a reduction corresponding to 20 €/ha. The greatest economic effects of the new CAP appear to be mainly due to the redistribution of direct payments.     

Multiple objectives and perceptions of optimal management: The Danish industrial fishery in the North Sea

Fisheries management involves many stakeholders with differentopinions about how the fishery should be optimally managed.This paper presents a multi-objective bio-economic model, whichis able to incorporate the preferences of managers and otherstakeholders. The model is a weighted goal programme coveringthe Danish industrial fishery. Economic, political and biologicalconcerns are considered simultaneously and, by applying thepreference structures of different stakeholders, it shows howthe optimally managed fishery would look from the perspectiveof managers and various interest groups. Managers, in this casethe Danish Ministry of Food, Agriculture and Fisheries, areprovided with a management tool that shows the consequencesof their preferences towards the objectives, and can be comparedwith optimal solutions as perceived by other stakeholders.     

On the efficiency of composting organic wastes

We develop a mathematical programming model for the analysis of a nationwide waste‐management system based on composting of organic wastes. The model integrates a wide range of engineering, environmental, and economic factors, including estimated production functions based on agronomic experimental data, as well as demand functions for vegetative agricultural products. The model is applied to the case of Israel, comprising 14 groups of municipalities as the source of organic municipal solid waste and wastewater‐treatment sludge, 8 composting plants, and 13 agricultural regions; the latter constitute the source of livestock manure and are the consumers of compost to be potentially applied to 42 crops. From a social point of view, 90% of the compost's potential production was found to be warranted. This efficient solution, however, does not emerge under the base‐year‐observed situation, largely because of the absence of source separation of organic municipal solid waste and the farmers' lack of awareness of compost's advantages as a substitute for conventional fertilizers and as a soil‐amending product. Consequently, most of the organic wastes are disposed of by landfilling, resulting in a loss of $102 million per year in terms of net social benefits. While the consumers of agricultural products are expected to benefit from a shift from the base‐year situation to the efficient solution, most of their gain is expected to come at the expense of the farming sector. Nevertheless, the appearance of the efficient solution does not depend on administrative compensation payments, but on the removal of bottlenecks. Potential government intervention strategies to promote the change are analyzed.     

Does a better diet reduce dependence on imports? The case of Tunisia

In the last 40 years, Tunisia has experienced—as many other developing and emerging countries—a dietary transition, which led to an increase in the consumption of sugar, fats, and animal products. This transition was accompanied by an increase in noncommunicable diseases, particularly cardiovascular diseases. Using mathematical programming, we optimized the Tunisian diet using the French dietary recommendations as constraints. Then, we used the Global Trade Analysis Project's constant elasticities of substitution in order to simulate the impact of fulfilling the nutrient recommendations on international trade and domestic supply. Using this approach, we showed that the Tunisian diet is rich in carbohydrates and sugar but lacks fibers, some minerals, and vitamins. The adherence to all recommendations would induce an imperative shift to less sugar and cereal-based products by reducing the import dependence on these products, but would result a dramatic increase in the domestic supply of products from animal origin, fruits, vegetables, and legumes.     

Interactivity and Soft Computing in Portfolio Management: Should Farmers Own Food and Agribusiness Stocks?

This article proposes a fully integrated and interactive elicitation-optimization procedure for portfolio management. A soft computing approach based on fuzzy logic is developed as an alternative to the traditional mean variance model and compromise programming approach. The models are applied to farmers to examine whether they should buy publicly traded food and agribusiness firms stocks rather than invest in a broader market stock portfolio. Results suggest that investments in publicly traded food and agribusiness stocks allow farmers to capture additional benefits beyond those of simply diversifying in the broader market.     

A Dynamic Model of the Firm: Structural Explanations of Key Empirical Findings

We derive a dynamic model of the firm in the spirit of the trade‐off theory of capital structure that explains firm behavior in terms of firm characteristics. We show our model is consistent with many important findings about the cross‐section of firms, including the negative relations between profitability and leverage, and between dividends and investment‐cash flow sensitivities. The model also explains the existence of zero‐debt firms and their observed characteristics. These results have been used to challenge the trade‐off theory and the assumption of perfect capital markets. We revisit these critiques and provide structural explanations for the regularities we replicate.     

Estimating Intertemporal Preferences for Natural Resource Allocation

In this article, we show how the degree of risk aversion, discounting, and preference for intertemporal substitution for a natural resource manager can be structurally estimated within a recursive utility framework. We focus on the management of a reservoir in California, and test the data for consistency with a recursive utility model specification versus standard time-additive separability. The results show that the data are consistent with a risk-averse manager with recursive preferences. The data also reject time-additive separability, with or without risk aversion, such as the standard constant relative risk aversion utility model. The improvement in model fit when recursive preferences are used is notable.     

九华山生态旅游资源开发

分析和评价了九华山生态游资源特点及发展生态旅游的制约因素,结合九华山佛教名胜及奇丽山水,提出了九华山生态旅游规划依据和项目设计的原则,设计出4种项目模式.     

PRICING A CLASS OF EXOTIC OPTIONS VIA MOMENTS AND SDP RELAXATIONS

We present a new methodology for the numerical pricing of a class of exotic derivatives such as Asian or barrier options when the underlying asset price dynamics are modeled by a geometric Brownian motion or a number of mean-reverting processes of interest. This methodology identifies derivative prices with infinite-dimensional linear programming problems involving the moments of appropriate measures, and then develops suitable finite-dimensional relaxations that take the form of semidefinite programs (SDP) indexed by the number of moments involved. By maximizing or minimizing appropriate criteria, monotone sequences of both upper and lower bounds are obtained. Numerical investigation shows that very good results are obtained with only a small number of moments. Theoretical convergence results are also established.     

乡村景观特色营造初探

在中国快速发展的城市化进程中,乡村景观规划显得尤为迫切。本文从乡村景观的概念入手,从政治、经济、文化、价值观等诸多方面的影响,来研究传统乡村景观特色的形成,并通过对乡村景观特色形成因素的分析,挖掘出乡土园林的根,进而探求现阶段致力营造乡村景观特色的努力方向。