The Use of Maximum Entropy to Estimate Input-Output Coefficients From Regional Farm Accounting Data

This paper proposes the use of the Generalised Maximum Entropy (GME) method to estimate input-output coefficients, which reflect the unobserved allocation of farm input accounting costs to the various outputs produced. The GME method uses Shannon's information criterion as a basis for estimation. The performance of the GME method is compared with three other estimation techniques: Ordinary Least Squares (OLS), Bayesian estimation, and Linear Programming (LP). The various methods are applied to accounting data from a sample of beef-dairy farms in Brittany, France. The analysis shows that the GME method offers an interesting alternative to “traditional” estimation methods. In contrast with the latter, though, the GME method is suitable to handle easily the problems of singularity, constrained estimation, and zero-observations. Moreover, due to its flexibility, transparency and relative ease of implementation, the GME method is of great value to practitioners. However, the sensitivity of the GME estimates with respect to the design of the prior information set needs to be investigated further.     

Estimating feed utilisation matrices using a cost function approach

In this paper a multiple-output cost function framework is proposed to construct national feed balances or feed utilisation matrices (FUMs). The framework is applied to the Belgian compound feed industry. For estimation purposes a Symmetrie Generalised McFadden (SGM) cost function is selected. The cost function is estimated using readily available time-series data for the period 1962–88. Unlike previous studies based on duality theory, this study exploits the properties of nonjointness in animal feed production to establish a complete FUM. The allocation of feed ingredients among different livestock categories as well as the composition of various compound feeds are identified. Also own- and cross-price elasticities of demand for feed ingredients by type of livestock are reported.     

A Competitive,Sustainable and Diverse Agriculture: A View of the CAP Beyond 2013 Pour une agriculture compétitive,durable and variée : un point de vue sur la PAC après 2013 Eine wettbewerbsfähige,nachhaltige und vielfältige Landwirtschaft: Ein Ausblick auf die GAP nach 2013

A Competitive, Sustainable and Diverse Agriculture: A View of the CAP Beyond 2013 New challenges make clear that past achievements of the CAP cannot be taken for granted. A strong European agricultural policy remains necessary after 2013, at the service of Europe’s citizens and agricultural sector. However, in order to realise the vision embedded in the European agricultural model, the CAP will have to evolve. Beyond dealing with the negative consequences of the economic crisis, more attention should go to competitiveness and entrepreneurship. The functioning of the supply chain should be improved leading to a fairer distribution of costs and benefits. Producer organisations should be expanded and strengthened. Work is needed to put into practice the concept of green growth and to explore the synergy between the demand for public goods and the need for higher farm income. An improved system of direct support remains justified, to compensate for extra costs and to stabilise income. The CAP post-2013 should offer a strong EU framework, able to meet shared challenges, with clear objectives and sufficient funding. Within that framework, diversity is a fact, and regions should be able to deploy CAP policies and funds in a more flexible way to accommodate local needs and problems and to be able to react to changing circumstances.     

Multi-scale narratives from an IA perspective: Part I. European and Mediterranean scenario development

Desertification in the Northern Mediterranean region can be effectively managed only through an understanding of the principal ecological, socio-cultural and economic drivers. Scenarios can play an important role in the understanding of such a complex system. Following the fundamentals of Integrated Assessment, narrative storylines were developed that are qualitative, participatory, and highly integrated. Multi-scale long-term (2030) storylines were developed for Europe, the Northern Mediterranean, and for four local cases. This paper discusses the methodology and results of the process of developing European and Mediterranean scenarios. In Part II, the local scenario development by means of scenario workshops is elaborated upon. European and Mediterranean scenarios were based on a set of three existing European scenarios, that were adapted to fit the specific issues in the Mediterranean region, using the so-called Factor-Actor-Sector (FAS) framework. Resulting scenarios were Convulsive Change (disruptive climate change); Big is Beautiful (oversized EU and powerful multinationals); and Knowledge is King (technological development and mass migration). It proved possible to use and enrich a set of existing European scenarios and to translate them to fit the Mediterranean region. A possible use of this type of narrative storylines is further illustrated in Part II.     

A differentiable homotopy to compute Nash equilibria of n-person games

Summary. The literature on the computation of Nash equilibria in n-person games is dominated by simplicial methods. This paper is the first to introduce a globally convergent algorithm that fully exploits the differentiability present in the problem. It presents an everywhere differentiable homotopy to do the computations. The homotopy path can therefore be followed by several numerical techniques. Moreover, instead of computing some Nash equilibrium, the algorithm is constructed in such a way that it computes the Nash equilibrium selected by the tracing procedure of Harsanyi and Selten. As a by-product of our proofs it follows that for a generic game the tracing procedure defines a unique feasible path. The numerical performance of the algorithm is illustrated by means of several examples. Received: December 21, 1999; revised version: December 27, 2000     

Structural Change for Economic Growth

As soon as the post-war era of rapid economic growth had come to an end in the early 1970s, the intellectural fashion being to swing towards a renewed appreciation of economic growth and the 'classical' factors of growth saving hard work, enterprise, innovation and a legal framework which secures the property rights to the rewards of material progress and facilitates flexible adjustment by a competitives system. Professor Wolfgang Kasper of the University of New South Wales in Australia argues that the major challenge for societies in West and East, North and South alike is now to make the supply side of the economy more elastic and responsive to new opparatunities and circumstances.     

Urbanization in some hierarchical urban models

"This paper examines two aspects of hierarchical urban models: the variations of total urban population and that of the urbanization ratio, in function of the number of hierarchical levels. Both variations are analysed through four categories of models. The complexity of the results suggests two approximations in order to make the analysis more tractable."