Existence of a competitive equilibrium in a one sector growth model with heterogeneous agents and irreversible investment

Summary. We prove existence of a competitive equilibrium in a version of a Ramsey (one sector) model in which agents are heterogeneous and gross investment is constrained to be non negative. We do so by converting the infinite-dimensional fixed point problem stated in terms of prices and commodities into a finite-dimensional Negishi problem involving individual weights in a social value function. This method allows us to obtain detailed results concerning the properties of competitive equilibria. Because of the simplicity of the techniques utilized our approach is amenable to be adapted by practitioners in analogous problems often studied in macroeconomics. Received: September 13, 2001; revised version: December 9, 2002 RID="*" ID="*" We are grateful to Tapan Mitra for pointing out errors as well as making very valuable suggestions. Thanks are due to Raouf Boucekkine and Jorge Duran for additional helpful discussions. We also thank an anonymous referee for his/her helpful comments. The second author acknowledges the financial support of the Belgian Ministry of Scientific Research (Grant ARC 99/04-235 “Growth and incentive design”) and of the Belgian Federal Goverment (Grant PAI P5/10, “Equilibrium theory and optimization for public policy and industry regulation”). Correspondence to: C. Le Van     

Understanding Empirical Boundaries: A Systems-Theoretical Avenue in Border Studies

The aim of this contribution is to present a conceptual framework with potential application across the interdisciplinary field of border studies. This framework should embrace interdisciplinarity and the contextual nature of borders. Based on the systems theory of Niklas Luhmann, it elaborates an understanding of borders as being related to a dynamic process of social bordering/bounding processes that involves spatial, social, and conceptual boundaries. By introducing the notion of ‘empirical boundary’, our framework aspires to bridge the gap between (radical) constructivist theorising and the analysis of physical realities involved in the (re)production of boundaries.     

An efficient budget allocation policy for decentralisation of responsibility for site decontamination projects

Selection and execution of site decontamination projects is often best left to local authorities, in accordance with the subsidiarity principle, even though the budget for such projects is made available through a central authority. In this paper we suggest a practical budget allocation policy which a central authority can employ to allocate budgets to local authorities, while still optimising the central authority's environmental objective function. The procedure is fully consistent with the principle of decentralisation of responsibility for selection and execution of projects, and requires a minimum information exchange between local and central levels. Despite the information asymmetry between local and central levels, incentive compatibility problems can be (partially) prevented by choosing an appropriate evaluation mechanism. At the same time, the procedure is computationally effective and efficient, and can guarantee a fair budget allocation, making it easy to implement and politically acceptable.     

The Potential Market for GM Rice with Health Benefits in a Chinese High-Risk Region

Genetically modified rice with a high folate content, i.e., folate biofortified rice, was recently developed to tackle folate deficiency. A consumer segmentation study is conducted to explore its market potential in the Chinese Shanxi Province, where the burden of folate deficiency is among the world’s highest. Cluster analysis of 451 rice consumers identified three segments: enthusiasts (14.2%), cautious (41.2%), and opponents (44.6%). Enthusiasts obtain the highest score of GM food knowledge and attitudes and have the highest GM rice acceptance rate, followed by cautious and reluctant consumers. Regarding GM food information, enthusiasts use almost entirely audiovisual channels and rely more on the industry, while other segments depend more on informal channels and anti-GM sources. Trust levels in these channels/sources differ between enthusiasts (high), opponents (neutral), and cautious (low). Based on multinomial regression, a targeted communication approach is recommended with a focus on female, cautious consumers and rural, low-educated opponents.     

Industry dynamics: Foundations for models with an infinite number of firms

This paper explores the connection between three important threads of economic research offering different approaches to studying the dynamics of an industry with heterogeneous firms. Finite models of the form pioneered by Ericson and Pakes (1995) capture the dynamics of a finite number of heterogeneous firms as they compete in an industry, and are typically analyzed using the concept of Markov perfect equilibrium (MPE). Infinite models of the form pioneered by Hopenhayn (1992), on the other hand, consider an infinite number of infinitesimal firms, and are typically analyzed using the concept of stationary equilibrium (SE). A third approach uses oblivious equilibrium (OE), which maintains the simplifying benefits of an infinite model but within the more realistic setting of a finite model. The paper relates these three approaches. The main result of the paper provides conditions under which SE of infinite models approximate MPE of finite models arbitrarily well in asymptotically large markets. Our conditions require that the distribution of firm states in SE obeys a certain “light-tail” condition. In a second set of results, we show that the set of OE of a finite model approaches the set of SE of the infinite model in large markets under a similar light-tail condition.     

Consumers’ Appreciation of Regional Certification Labels: A Pan‐European Study

Successful regional products, such as Florida oranges, Idaho potatoes and Parma ham, often have to compete against products passing themselves off as the authentic product using the exact same name. This unfair competition misleads consumers, discourages small‐ and medium‐sized enterprises (SMEs) from marketing products based on their region of origin, and may end up hurting rural economies. To protect consumers, and support SMEs and rural economies, many countries around the world have introduced regulations enabling SMEs to legally protect the names of their regional products. The success of these regulations largely depends on consumers’ appreciation of regional certification labels that inform consumers that the name of the regional product is protected and that it denotes the authentic product. To gain an understanding about consumers’ appreciation of regional certification labels, this paper investigates consumers’ image of these labels and proposes a model that relates this image to consumers’ willingness to buy and pay for protected regional products. The model is tested based on Regulation No. 2081/92 that was introduced by the EEC allowing European SMEs to protect their regional products and market their products with a protected‐designation‐of‐origin (PDO) label. Structural equation modelling results suggest that consumers’ image of regional certification labels consists of a quality warranty dimension and an economic support dimension, which positively relate to consumers’ willingness to buy and pay for the protected regional product. Protecting regional products and marketing them with regional certification labels may be beneficial for SMEs producing and marketing regional products. Policy and managerial implications are discussed.     

Optimal surveillance against foot‐and‐mouth disease: the case of bulk milk testing in Australia

Previous foot‐and‐mouth disease (FMD) outbreaks and simulation‐based analyses suggest substantial payoffs from detecting an incursion early. However, no economic measures for early detection have been analysed in an optimising framework. We investigate the use of bulk milk testing (BMT) for active surveillance against an FMD incursion in Australia. We find that BMT can be justified, but only when the FMD entry probability is sufficiently high or the cost of BMT is low. However, BMT is well suited for post‐outbreak surveillance, to shorten the length of time and size of an epidemic and to facilitate an earlier return to market.