Policy networks of organic farming in Europe

This report presents an analysis of national and supranational organic farming policy networks in Europe. The aim of the national level analysis is to examine the different structures of policy making and how these depend on the country-specific conditions. The aim of the EU level analysis is twofold: firstly, the political structure of organic farming is examined in the context of the Common Agricultural Policy (CAP); secondly, the research investigates the attitudes of EU level policy makers towards organic farming and their acceptance of specific organic farming policy instruments

A Modelling Approach for Evaluating Agri-Environmental Policies at Sector Level

This paper presents a new approach to evaluate the cost effectiveness of agri-environmental policies at sector level. Policy uptake, cumulative environmental effects and public expenditure are identified as the main determinants of cost-effectiveness. On the basis of the sector-consistent, comparative-static, farm group model FARMIS, the determinants of policy cost-effectiveness at sector level are addressed. Firstly, intensity levels for the FARMIS activities are defined in order to model uptake of agri-environmental policies with FARMIS, secondly, life-cycle assessment data is attached to these intensity levels to determine environmental effects of the policies and thirdly, public expenditure is calculated under consideration of transaction costs. This paper concludes delineating the strengths and limitations of the approach

Spin Chains as Perfect Quantum State Mirrors

Quantum information transfer is an important part of quantum information processing. Several proposals for quantum information transfer along linear arrays of nearest-neighbor coupled qubits or spins were made recently. Perfect transfer was shown to exist in two models with specifically designed strongly inhomogeneous couplings. We show that perfect transfer occurs in an entire class of chains, including systems whose nearest-neighbor couplings vary only weakly along the chain. The key to these observations is the Jordan-Wigner mapping of spins to noninteracting lattice fermions which display perfectly periodic dynamics if the single-particle energy spectrum is appropriate. After a half-period of that dynamics any state is transformed into its mirror image with respect to the center of the chain. The absence of fermion interactions preserves these features at arbitrary temperature and allows for the transfer of nontrivially entangled states of several spins or qubits.Comment: Abstract extended, introduction shortened, some clarifications in the text, one new reference. Accepted by Phys. Rev. A (Rapid Communications

Impurity spin relaxation in S=1/2 XX chains

Dynamic autocorrelations $$ (\alpha=x,z) of an isolated impurity spin in a S=1/2 XX chain are calculated. The impurity spin, defined by a local change in the nearest-neighbor coupling, is either in the bulk or at the boundary of the open-ended chain. The exact numerical calculation of the correlations employs the Jordan-Wigner mapping from spin operators to Fermi operators; effects of finite system size can be eliminated. Two distinct temperature regimes are observed in the long-time asymptotic behavior. At T=0 only power laws are present. At high T the x correlation decays exponentially (except at short times) while the z correlation still shows an asymptotic power law (different from the one at T=0) after an intermediate exponential phase. The boundary impurity correlations follow power laws at all T. The power laws for the z correlation and the boundary correlations can be deduced from the impurity-induced changes in the properties of the Jordan-Wigner fermion states.Comment: Final version to be published in Phys. Rev. B. Three references added, extended discussion of relation to previous wor

COMPLETE SOLUTION OF THE XXZ-MODEL ON FINITE RINGS. DYNAMICAL STRUCTURE FACTORS AT ZERO TEMPERATURE.

The finite size effects of the dynamical structure factors in the XXZ-model are studied in the euclidean time $(\tau)$-representation. Away from the critical momentum $p=\pi$ finite size effects turn out to be small except for the large $\tau$ limit. The large finite size effects at the critical momentum $p=\pi$ signal the emergence of infrared singularities in the spectral $(\omega)$-representation of the dynamical structure factors.Comment: PostScript file with 12 pages + 11 figures uuencoded compresse

Consumer attitudes towards organic versus conventional food with specific quality attributes

This paper describes the findings from a consumer survey conducted as part of the EU-funded research project QualityLowInputFood (QLIF). The objective was to segment occasional organic consumers with regard to their preferences for organic, conventional and conventional-plus products, i.e., conventional products with a specific attribute that also applies to organic products. In other words, these conventional-plus products are placed between organic and conventional food products. In addition, we aimed at analysing differences between consumer segments regarding their price sensitivity and attitudes towards food. The survey used choice experiments to investigate occasional organic consumer preferences for the different types of products. In subsequent standardized face-to-face interviews we collected data on consumer attitudes towards food that could explain the observed preferences. The attitudes were summarized in attitude factors, using factor analysis. The responses from the interviews and choice experiments were analysed by latent class models. These econometric models were used to identify segments within a group of individuals for their preference structure and to relate membership in each segment to consumer characteristics. Two segments of occasional organic consumers were identified. Consumers in segment 1 strongly preferred organic products and were less price sensitive. Furthermore, consumers in this segment showed a significantly higher level of agreement with most of the investigated attitude factors than consumers in segment 2. The latter consisted of consumers who were significantly more price sensitive and preferred conventional-plus and conventional products rather than organic products. Communicating quality attributes represents a promising marketing tool of product differentiation and information for both organic and conventional food marketers. The price sensitivity of parts of occasional organic consumers suggests that the perceived price-performance ratio of organic products needs to be increased by targeted pricing and communication strategies integrating product-relevant information. If not, conventional-plus products, representing a cheaper alternative, might be preferred by parts of the occasional organic consumers

Dynamic properties of the spin-1/2 XY chain with three-site interactions

We consider a spin-1/2 XY chain in a transverse (z) field with multi-site interactions. The additional terms introduced into the Hamiltonian involve products of spin components related to three adjacent sites. A Jordan-Wigner transformation leads to a simple bilinear Fermi form for the resulting Hamiltonian and hence the spin model admits a rigorous analysis. We point out the close relationships between several variants of the model which were discussed separately in previous studies. The ground-state phases (ferromagnet and two kinds of spin liquid) of the model are reflected in the dynamic structure factors of the spin chains, which are the main focus in this study. First we consider the zz dynamic structure factor reporting for this quantity a closed-form expression and analyzing the properties of the two-fermion (particle-hole) excitation continuum which governs the dynamics of transverse spin component fluctuations and of some other local operator fluctuations. Then we examine the xx dynamic structure factor which is governed by many-fermion excitations, reporting both analytical and numerical results. We discuss some easily recognized features of the dynamic structure factors which are signatures for the presence of the three-site interactions.Comment: 28 pages, 10 fugure

Produktionsverfahren des Ökologischen Landbaus in Baden-Württemberg

Diese Datensammlung ist als Hilfsmittel für die Betriebsplanung gedacht. Es stellt standardisierte Produktionsverfahren des Ökolandbaus in Baden-Württemberg dar, wobei die wichtigsten Verfahren des Ackerbaus, der Rindviehhaltung, des Feldfutterbaus und des Grünlandes aufgeführt sind. Die Ausgleichszahlungen und Prämien sind bis zum Jahr 2002/2003 aufgeführt: Für die Deckungsbeitragsrechnung wurde das Jahr 2002/2003 berücksichtigt. Als Maßnahme des MEKA (Marktentlastungs- und Kulturlandschaftsausgleichsprogramm) ist die Beibehaltung des ökologischen Landbaus in die Berechnung mit einbezogen

Bio mit Gesicht - Erfolgschancen einer kundennahen und innovativen Marketingstrategie

Mangelndes Vertrauen in Bio-Produkte wirkt als eine zentrale Kaufbarriere. Mit der Marketingstrategie Bio mit Gesicht (BMG) soll die Anonymität von Produkten aufgehoben und Vertrauen geschaffen werden, indem die Erzeuger und Verarbeiter im Internet vorgestellt werden. Ziel des Projekts "Bio mit Gesicht – Erfolgschancen einer kundennahen und innovativen Marketingstrategie“ war es, die Markteinführung der Produktlinie BMG wissenschaftlich zu begleiten und praxisrelevante Aussagen über die Konzeption zukünftiger Marketingstrategien zu treffen. Dabei wurde im Rahmen einer quantitativen und einer qualitativen Studie untersucht, worauf das Vertrauen in Bio-Produkte grundsätzlich beruht und ob BMG geeignet ist, das Vertrauen in Bio-Produkte zu steigern. Die Studien zeigen, dass die Kennzeichnung von Bio-Lebensmitteln mit Bio-Labels eine zentrale Rolle dabei spielt, wie Konsumenten deren Vertrauenswürdigkeit beurteilen. Bio-Produkte, die ein Verbandslabel aufweisen, genießen das höchste Vertrauen, gefolgt von staatlichen Labels. Trotz seines geringen Bekanntheitsgrads wirkt auch das BMG-Logo vertrauensbildend. Offenbar erweckt bereits allein das signalgebende Wort „bio“ im Label Vertrauen. Auch schaffen Einkaufsstätten Vertrauen, die aus Sicht der Konsumenten Bio-Produkte aus Überzeugung verkaufen. Regionalität erhöht ebenfalls die Vertrauenswürdigkeit eines Bio-Produkts signifikant. Am höchsten ist das Vertrauen in Bio-Lebensmittel unter Konsumenten, die Bio-Lebensmittel überwiegend in Bio-Läden kaufen. Im Gegensatz zum BMG-Label steigert BMG als Rückverfolgbarkeitssystem via Internet das Vertrauen in Bio-Produkte derzeit kaum. Doch insbesondere durch die zunehmende Verbreitung von Smartphones und den damit verbundenen Vorteil, Produktinformationen noch vor dem Einkauf abrufen zu können, könnte die Bedeutung von BMG zukünftig steigern. Auch die wachsende Bedeutung von elektronischen Lesegeräten, mit denen sich Artikeldaten bereits während des Lebensmitteleinkaufs abrufen lassen, steigert das Potenzial von Rückverfolgbarkeitssystemen. Die Analyse der Zugriffszahlen zeigte zudem, dass in Zeiten eines Lebensmittelskandals (z.B. Dioxin in Eiern, EHEC) die Besucherzahlen auf der Internetseite von BMG deutlich steigen