20 research outputs found
Technische Effizienz von diversifizierten Ökobetrieben in der Schweiz, Österreich und Süddeutschland
Der vorliegende Beitrag untersucht die Auswirkungen der Diversifizierung auf die technische Effizienz von Ökobetrieben in der Schweiz, Österreich und Süddeutschland. Technische Effizienz wird modelliert mit Hilfe einer stochastischen Distanzfrontier kombiniert mit einem Metafrontier-Modell. Diversifizierung wirkt negativ auf die Effizienz der Betriebe. Die Studie zeigt auch, dass landwirtschaftliche Direktzahlungen negativ auf die betriebliche Effizienz auswirken
IPASIR-UP: User Propagators for CDCL
Modern SAT solvers are frequently embedded as sub-reasoning engines into more complex tools for addressing problems beyond the Boolean satisfiability problem. Examples include solvers for Satisfiability Modulo Theories (SMT), combinatorial optimization, model enumeration and counting. In such use cases, the SAT solver is often able to provide relevant information beyond the satisfiability answer. Further, domain knowledge of the embedding system (e.g., symmetry properties or theory axioms) can be beneficial for the CDCL search, but cannot be efficiently represented in clausal form. In this paper, we propose a general interface to inspect and influence the internal behaviour of CDCL SAT solvers. Our goal is to capture the most essential functionalities that are sufficient to simplify and improve use cases that require a more fine-grained interaction with the SAT solver than provided via the standard IPASIR interface. For our experiments, we extend CaDiCaL with our interface and evaluate it on two representative use cases: enumerating graphs within the SAT modulo Symmetries framework (SMS), and as the main CDCL(T) SAT engine of the SMT solver cvc5
Stall- und weidebasierte Milchproduktionssysteme Modellbetriebsanalysen zur Wirtschaftlichkeit unter österreichischen Produktionsbedingungen
In a whole-system study in lowland of Central Switzerland from 2007 - 2010 compared the performance, efficiency, land productivity and profitability of indoor-feeding (SH)
dairy production with that of pasture-based feeding (VW) dairy production. In the present study these experimental results were economically evaluated under Austrian
market und production conditions. Therefore conventional and organic model farms were created and analyzed using full cost accounting. In comparison to the barn feeding strategy a higher farm income, income per labor unit were achieved with the pasture-based feeding strategy. These economic differences were more pronounced under organic than conventional conditions
Improving Farm Competitiveness through Farm-Investment Support: a Propensity Score Matching Approach
The heterogeneity of farms and the problem of self-selection are challenging the
evaluation of treatments in agriculture. This is particularly the case for rural development measures whit voluntary participation and heterogeneous outcomes. But knowledge about the selection mechanisms for a certain treatment, in combination with econometric methods, can help to overcome these problems. One of these promising methods is the Propensity Score Matching
(PSM) approach. In this paper we apply PSM in order to obtain treatment effects from the
agricultural investment support programme in Austria on the farm income. We also test the
robustness of the results to hidden bias with sensitivity analysis. Furthermore we split the sample in more homogenous subsamples in order to increase the robustness of the results. The results
show that treatment effects differ by a large amount for the subsamples and that splitting leads to slightly more robust results
Matching Efficiency Results of Organic Farms
Organic farms work under very heterogeneous natural-site and socio-economic
conditions. This heterogeneity is of clear relevance for economic efficiency and for
the decision of farms to convert to organic farming. In order to produce proper
results efficiency analysis must consider such heterogeneity and self-selection
aspects. This applies in particular to data envelopment analysis, since this technique
does not calculate error terms, but include heterogeneity into efficiency results. One
way to control for such effects is matching. Matching is based on the assumption that
under a given vector of observable variables, the outcome of one individual is
independent of the adoption of a specific treatment. In our paper we present how to
implement matching into efficiency analysis of organic farms. We give a brief
overview on literature applying this technique and we discuss which insights the
application of matching might contribute to the current discussion on organic
farming
Structural Change and Farm Investment Support in Austria
The effects of policy supported farm investments on structural change in agriculture have been studied rarely. The heterogeneity of farms and the problem of self-selection are challenging the evaluation of treatments in agriculture. Econometric methods can help to overcome these problems. In this paper, we apply a conditional Difference-in-Difference (DiD) estimation, where we combine Direct Covariate Matching with a DiD estimation. Our dataset consist of more than 90,000 farms. In order to measure the development and the heterogeneity of the effects after the investment we look at several years and different farm groups separately. Our results show that investing farms significantly enlarge and intensify their production more than non-investing farms. Furthermore, the results indicate that investments are often not completely implemented short-term but require a certain implementation period. This applies in particular to cattle farming
Field sizes and the future of farmland biodiversity in European landscapes
Lower diversity of plant and animal farmland species are usually reported where cropland has been aggregated into larger fields, which raises prospects of curbing declines in European farmland biodiversity and associated ecosystem services by halting trends to field size increases associated to agricultural intensification, without having to set aside arable land for conservation. Here, we consider the factors underlying trade-offs between farmer income and biodiversity as mediated by field size at local and landscape scales, and how these trade-offs may be overcome. Field sizes are still increasing, facilitated by increasing farm sizes and land consolidation. Decreases in working time and fuel expenses when fields are larger, uptake of larger machinery and subsidies favoring larger farms provide incentives to manage land in larger units, putting farmland biodiversity further at risk. Yet, field size-mediated ecological–economic trade-offs are largely ignored in policy and research. We recommend internalizing the ecological effects of changes in landscape-scale field size into land consolidation scheme design, ensuring that EU Common Agricultural Policy post-2020 rewards farmers that maintain and recreate fine-grained landscapes where these are essential for farmland biodiversity targets, and reducing economic–ecological trade-offs by stimulating agricultural research and innovation for economically efficient yet biodiversity-friendly farming in fine-grained landscapes
Modelling the effects of low-input dairy farming using bookkeeping data from Austria
Despite the ongoing trend of higher intensities in dairy farming, some farmers select
rather low-input systems. We identify such system in an agricultural bookkeeping
dataset and assess economic effects of this system selection under volatile prices
situations using cluster analysis and direct covariates matching. We find one lowinput
cluster with low levels of input use and three clusters with rather higher input
levels. Those clusters differ in site conditions, farm size and milk production. After
applying the matching methodology, the results indicate that choosing a low-input
system does not affect farm income but reduces the work load and borrowed capital
even under volatile markets
Strategies regarding input use on dairy farms in Austria - results of a cluster and matching analysis
In order to increase competitiveness of their farms, dairy farmers select certain strategies regarding input use. We identify these strategies in an agricultural bookkeeping dataset and assess economic impacts of the strategy selection under volatile prices situations using cluster analysis and direct covariates matching. We find one low-input cluster with low levels of input use and three clusters with rather higher input levels. Those clusters differ in site conditions, farm size and milk production but have similar farm income. Furthermore the results indicate that low-input farms are competitive under volatile markets