Modelling the Spatial Structure of Pig Production in Denmark

In Denmark, the concentration of pig production is highest in the western part of the country. However, there may be even larger local differences in the number of pigs produced. In this study we analyze the determinants of the location of pig production in Denmark with particular focus on spatial externalities and the interaction between the location of pig production and upstream sector and slaughterhouses. It is the assumption that the location of slaughterhouses is influenced by the location of the primary producers, implying that this variable is endogenous, whereas the location of primary producers is independent of the location of slaughterhouses. This is due to the fact that transportation costs of pigs are paid by the cooperatives owning the slaughterhouses. This assumption is tested applying a spatial econometric model. The model is estimated for 1999 and 2004. Furthermore, the impact of negative environmental externalities of pig production on location is analyzed. The results show that spatial externalities have a positive effect on the location of pig production whereas environmental regulation has a negative effect on location.Agglomeration, Externalities, Spatial Econometrics, Polluted Production, Livestock Production/Industries,

Agglomeration Externalities and Technical Efficiency in Pig Production

The objective of the paper is to assess the effects of agglomeration on technical efficiency of French pig farms. We use a two-stage method to evaluate the effects of agglomeration on technical efficiency. The first stage consists in calculating pig activity’s efficiency scores with the non-parametric method Data Envelopment Analysis (DEA). The second stage is a truncated regression of these scores on agglomeration variables. Data are for 899 French pig producers in 2004. Results suggest that these farms were as much affected by positive agglomeration externalities (that are knowledge spillovers due to farms’ density, and also arise from farms’ closeness to downstream market) as any other businesses. There was however no evidence of negative externalities in the form of constraints in farmers’ land demand due to legal disposition relating to manure spreading.Agglomeration, Externalities, Data Envelopment Analysis, Industrial Organization, Livestock Production/Industries,

On-Farm Food Safety and Environmental Farm Plans: A Conceptual Framework for Identifying and Classifying Benefits and Costs

This series of six reports entitled: "On-Farm Food Safety and Environmental Farm Plans: Identifying and Classifying Benefits and Costs" was initiated soon after the launch of the Agricultural Policy Framework (APF) in 2002. The APF recognized the importance of food safety and environmental concerns for the future growth of the agriculture and Agri-food sector. For this reason, Agriculture and Agri-Food Canada (AAFC) commissioned this series of reports to develop a conceptual framework to strengthen our understanding of the potential benefit and cost implications of On-farm Food Safety (OFFS) and Environmental Farm Plans (EFP) that were key components of the APF. The reports were prepared by a group of academics with extensive knowledge of the agriculture and Agri-food sector and issues related to food safety, traceability and the environment. The first report presents a summary of the findings in the five main reports in the series. The second report presents the conceptual framework that was developed to help identify qualitatively the potential benefits and costs that the various players in the agriculture and agri-food supply chain would face in implementing OFFS and EFP programs. The third report applies this framework to pork, the fourth, to beef, the fifth, to grains and the sixth, to dairy. In general, benefits and costs are divided into both demand and supply side effects. In addition, both public and private costs and benefits are considered, especially since they help indicate where a role for government might be required and where markets are not working as well as they might. Based on these preliminary qualitative assessments, the beef and pork sector have more to gain from HACCP-based OFFS and EFP initiatives, due to their ability to gain market share from marketing their products internationally, while the grains sector already benefits internationally from its high quality reputation and the dairy sector is restricted to produce only for the domestic market. However, more work is required in these areas to validate and quantify costs and benefits.Agribusiness, Agricultural and Food Policy, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Production Economics, Resource /Energy Economics and Policy,

Why Judges Applying the Daubert Trilogy Need to Know About the Social, Institutional, and Rhetorical - And Not Just the Methodological - aspects of Science

In response to the claim that many judges are deficient in their understanding of scientific methodology, this Article identifies in recent cases (1) a pragmatic perspective on the part of federal appellate judges when they reverse trial judges who tend to idealize science (i.e., who do not appreciate the local and practical goals and limitations of science), and (ii) an educational model of judicial gatekeeping that results in reversal of trial judges who defer to the social authority of science (i.e., who mistake authority for reliability). Next, this Article observes that courts (in the cases it analyzes) are not interested in pragmatically constructing legal science, but rather attempt to ensure that science itself, conceived pragmatically (i.e., without idealizing science), is appropriated in law. This Article concludes that trial judges who fail to appreciate the social, institutional, and rhetorical aspects of science tend to reject reliable—albeit pragmatic—science, welcome unreliable—albeit authoritative— science, and thereby create a body of legal science that is out of sync with mainstream science

On the Early History of Current Algebra

The history of Current Algebra is reviewed up to the appearance of the Adler-Weisberger sum rule. Particular emphasis is given to the role current algebra played for the historical struggle in strong interaction physics of elementary particles between the S-matrix approach based on dispersion relations and field theory. The question whether there are fundamental particles or all hadrons are bound or resonant states of one another played an important role in this struggle and is thus also regarded.Comment: 17 page

Identifying Advantages and Disadvantages of Variable Rate Irrigation – An Updated Review

Variable rate irrigation (VRI) sprinklers on mechanical move irrigation systems (center pivot or lateral move) have been commercially available since 2004. Although the number of VRI, zone or individual sprinkler, systems adopted to date is lower than expected there is a continued interest to harness this technology, especially when climate variability, regulatory nutrient management, water conservation policies, and declining water for agriculture compound the challenges involved for irrigated crop production. This article reviews the potential advantages and potential disadvantages of VRI technology for moving sprinklers, provides updated examples on such aspects, suggests a protocol for designing and implementing VRI technology and reports on the recent advancements. The advantages of VRI technology are demonstrated in the areas of agronomic improvement, greater economic returns, environmental protection and risk management, while the main drawbacks to VRI technology include the complexity to successfully implement the technology and the lack of evidence that it assures better performance in net profit or water savings. Although advances have been made in VRI technologies, its penetration into the market will continue to depend on tangible and perceived benefits by producers

A Qualitative Assessment of the Benefits and Costs of On-Farm Food Safety and Environmental Farm Plans in the Dairy Sector

This series of six reports entitled: "On-Farm Food Safety and Environmental Farm Plans: Identifying and Classifying Benefits and Costs" was initiated soon after the launch of the Agricultural Policy Framework (APF) in 2002. The APF recognized the importance of food safety and environmental concerns for the future growth of the agriculture and Agri-food sector. For this reason, Agriculture and Agri-Food Canada (AAFC) commissioned this series of reports to develop a conceptual framework to strengthen our understanding of the potential benefit and cost implications of On-farm Food Safety (OFFS) and Environmental Farm Plans (EFP) that were key components of the APF. The reports were prepared by a group of academics with extensive knowledge of the agriculture and Agri-food sector and issues related to food safety, traceability and the environment. The first report presents a summary of the findings in the five main reports in the series. The second report presents the conceptual framework that was developed to help identify qualitatively the potential benefits and costs that the various players in the agriculture and agri-food supply chain would face in implementing OFFS and EFP programs. The third report applies this framework to pork, the fourth, to beef, the fifth, to grains and the sixth, to dairy. In general, benefits and costs are divided into both demand and supply side effects. In addition, both public and private costs and benefits are considered, especially since they help indicate where a role for government might be required and where markets are not working as well as they might. Based on these preliminary qualitative assessments, the beef and pork sector have more to gain from HACCP-based OFFS and EFP initiatives, due to their ability to gain market share from marketing their products internationally, while the grains sector already benefits internationally from its high quality reputation and the dairy sector is restricted to produce only for the domestic market. However, more work is required in these areas to validate and quantify costs and benefits.Agribusiness, Agricultural and Food Policy, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Marketing, Production Economics, Resource /Energy Economics and Policy,

Overview of the Development and Applications of a Conceptual Framework for Analyzing Benefits and Costs of On-Farm Food Safety and Environmental Farm Plans

This series of six reports entitled: "On-Farm Food Safety and Environmental Farm Plans: Identifying and Classifying Benefits and Costs" was initiated soon after the launch of the Agricultural Policy Framework (APF) in 2002. The APF recognized the importance of food safety and environmental concerns for the future growth of the agriculture and Agri-food sector. For this reason, Agriculture and Agri-Food Canada (AAFC) commissioned this series of reports to develop a conceptual framework to strengthen our understanding of the potential benefit and cost implications of On-farm Food Safety (OFFS) and Environmental Farm Plans (EFP) that were key components of the APF. The reports were prepared by a group of academics with extensive knowledge of the agriculture and Agri-food sector and issues related to food safety, traceability and the environment. The first report presents a summary of the findings in the five main reports in the series. The second report presents the conceptual framework that was developed to help identify qualitatively the potential benefits and costs that the various players in the agriculture and agri-food supply chain would face in implementing OFFS and EFP programs. The third report applies this framework to pork, the fourth, to beef, the fifth, to grains and the sixth, to dairy. In general, benefits and costs are divided into both demand and supply side effects. In addition, both public and private costs and benefits are considered, especially since they help indicate where a role for government might be required and where markets are not working as well as they might. Based on these preliminary qualitative assessments, the beef and pork sector have more to gain from HACCP-based OFFS and EFP initiatives, due to their ability to gain market share from marketing their products internationally, while the grains sector already benefits internationally from its high quality reputation and the dairy sector is restricted to produce only for the domestic market. However, more work is required in these areas to validate and quantify costs and benefits.Agribusiness, Agricultural and Food Policy, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Production Economics, Resource /Energy Economics and Policy,

Actions of the braid group, and new algebraic proofs of results of Dehornoy and Larue

This article surveys many standard results about the braid group with emphasis on simplifying the usual algebraic proofs. We use van der Waerden's trick to illuminate the Artin-Magnus proof of the classic presentation of the algebraic mapping-class group of a punctured disc. We give a simple, new proof of the Dehornoy-Larue braid-group trichotomy, and, hence, recover the Dehornoy right-ordering of the braid group. We then turn to the Birman-Hilden theorem concerning braid-group actions on free products of cyclic groups, and the consequences derived by Perron-Vannier, and the connections with the Wada representations. We recall the very simple Crisp-Paris proof of the Birman-Hilden theorem that uses the Larue-Shpilrain technique. Studying ends of free groups permits a deeper understanding of the braid group; this gives us a generalization of the Birman-Hilden theorem. Studying Jordan curves in the punctured disc permits a still deeper understanding of the braid group; this gave Larue, in his PhD thesis, correspondingly deeper results, and, in an appendix, we recall the essence of Larue's thesis, giving simpler combinatorial proofs.Comment: 51`pages, 13 figure