Monoidal derivators and additive derivators

One aim of this paper is to develop some aspects of the theory of monoidal derivators. The passages from categories and model categories to derivators both respect monoidal objects and hence give rise to natural examples. We also introduce additive derivators and show that the values of strong, additive derivators are canonically pretriangulated categories. Moreover, the center of additive derivators allows for a convenient formalization of linear structures and graded variants thereof in the stable situation. As an illustration of these concepts, we discuss some derivators related to chain complexes and symmetric spectra

An empirical examination of repeated auctions for biodiversity conservation contracts

The European Union’s Council Regulation on support for rural development by the European Agricultural Fund for Rural Development has introduced auctioning as a new instrument for granting agri-environmental payments and awarding conservation contracts for the recent multi-annual budgetary plan. This paper therefore deals with the conception and results of two case study auctions for conservation contracts. Results of two field experiments show much differentiated bid prices in the model-region and budgetary cost-effectiveness gains of up to 21% in the first auction and up to 36% in the repeated auction. Besides these promising results, some critical aspects as well as lessons to be learned will also be discussed in this paper to improve the design and performance of upcoming conservation auctions.agri-environmental policy, discriminatory-price auction, multi-unit auction, ecological services, plant biodiversity, experimental economics

A New-Growth Perspective on Non-Renewable Resources

This article reviews issues related to the incorporation of non-renewable resources in the theory of economic growth and development. As an offshoot of the new growth theory of the last two decades a series of contributions have studied endogenous technical change in relation to resource scarcity. We discuss the main approaches within this literature and consider questions like: How is the new literature related to the wave of resource economics of the 1970s? What light is thrown on the limits-to-growth issue? Does the existence of non-renewable resources have implications for the controversies within new growth theory?endogenous growth; innovation; non-renewable resources; knife-edge conditions; robustness; limits to growth

Auctions in an outcome-based payment scheme to reward ecological services in agriculture – Conception, implementation and results

This paper presents an outcome-based payment scheme to reward ecological services in agriculture. It was designed by a research group from the Georg-August-University of Goettingen. Starting in January 2004 the payment scheme is tested upon it’s implementation as an agri-environmental program in a model-region (administrative district Northeim in the south of Lower Saxony – Germany). The intention of the program is to overcome the disadvantages of existing and mostly action-orientated agri-environmental programs, especially those in the European Union. The design of the payment scheme is based on fundamental criteria of market economy such as supply and demand and it integrates auctions as an award procedure. Furthermore it is outcome-based and considers the interests of the local people and the relevant stakeholders and their demand for botanical diversity. The main research topic is to explore the use of auction in agri-environmental programs seen from an transaction cost economics point of view. Therefor the relevant farmers transaction costs will be measured. In the course of this research it is essential to analyse the practical relevance of transaction costs and to draw conclusions to their theoretical foundation. Results as well as of the first auction and two surveys of local farmers already show, that this payment scheme is not just an theoretical construct but that it is already practicable in the model-region. However further research is needed to make sure that at the end of the current case study this payment scheme is authorised from an ecological economics point of view and has a high potential to be a part of a sustainable future agri-environmental policy in Germany and the European Union.

Abstract representation theory of Dynkin quivers of type A

We study the representation theory of Dynkin quivers of type A in abstract stable homotopy theories, including those associated to fields, rings, schemes, differential-graded algebras, and ring spectra. Reflection functors, (partial) Coxeter functors, and Serre functors are defined in this generality and these equivalences are shown to be induced by universal tilting modules, certain explicitly constructed spectral bimodules. In fact, these universal tilting modules are spectral refinements of classical tilting complexes. As a consequence we obtain split epimorphisms from the spectral Picard groupoid to derived Picard groupoids over arbitrary fields. These results are consequences of a more general calculus of spectral bimodules and admissible morphisms of stable derivators. As further applications of this calculus we obtain examples of universal tilting modules which are new even in the context of representations over a field. This includes Yoneda bimodules on mesh categories which encode all the other universal tilting modules and which lead to a spectral Serre duality result. Finally, using abstract representation theory of linearly oriented $A_n$-quivers, we construct canonical higher triangulations in stable derivators and hence, a posteriori, in stable model categories and stable $\infty$-categories

The transferability and performance of payment-by-results biodiversity conservation procurement auctions: empirical evidence from northernmost Germany

Managed grasslands contribute in a number of ways to the biodiversity of European agricultural landscapes and provide a wide range of ecosystem services that are also of socio-economic value. Against the background of a rapid biodiversity loss in agricultural landscapes, increasing attention is being paid to farming practices that enhance ecosystem services. Therefore developing cost-effective conservation payment schemes is the main challenge facing present European agri-environmental policy. This paper deals with the transferability of a payment scheme that combines a payment-by-results approach with the use of discriminatory-price conservation procurement auctions in order to improve the cost-effectiveness of conservation schemes for grassland plant biodiversity. Hence the design, implementation and results of the adapted case-study payment scheme in the county Steinburg in the northernmost federal state of Germany (Schleswig-Holstein) will be focussed. Results concerning the ecological-effectiveness of the payment-by-results approach as well bid-prices and potential cost-effectiveness gains by the use of conservation procurement auctions point out that it was possible to transfer the payment scheme successfully to another region, whereby the adapted case-study even outperforms the original case-study.agri-environmental policy, discriminatory-price auction, ecological services, experimental economics, multi-unit auction, payment-by-results, plant biodiversity, rural development.