Towards a more appropriate method for determining the optimal scale of production units

In this paper the overall diseconomies experienced beyond certain production unit scale thresholds are investigated. These are due to several costs, including those relating to the consumption of non- renewable resources, which firms have generally not internalised, to the extent that they can operate far beyond the socially optimal scale. Economic instruments such as environmental taxes may induce a shift towards marginally more sustainable production levels for a plant of a given size, but they are not designed to affect the plant size itself. This paper suggests a method for determining a socially optimal scale, by focussing on the factors which determine optimality. The results of applying this method show that establishing the scale of production units at a social optimum rather than a private one implies a significant decrease in scale for most economic activities. Downscaling has significant economic welfare and environmental advantages. Incentives linked to the factors which determine the social optimum are put forward as measures for inducing a shift towards an optimal size for production units.optimal scale, sustainable production, market areas

Towards a more appropriate method for determining the optimal scale of production units

This paper asserts that beyond certain scale thresholds several factors contribute to diseconomies of scale for individual production units, particularly with regard to the costs of non-renewable resource consumption. Economic instruments such as environmental taxes may induce a shift towards marginally more sustainable production levels for a plant of a given size, but they are not designed to affect the plant size itself. This paper suggests a methodology for determining optimal scale more appropriately. The results show that establishing the scale of production units at a social optimum rather than a private one implies a significant decrease in scale for most economic activities. Downscaling also has significant economic welfare and environmental advantages. Incentives linked to the factors which determine the social optimum are put forward as measures for inducing a shift towards an optimal size for production units

Two-wavelength switching with a distributed-feed back semiconductor optical amplifier (DFBSOA)

Switching of a signal beam by another control beam at different wavelength is demonstrated experimentally using the optical bistability occurring in a 1.55 mm-distributed feedback semiconductor optical amplifier (DFBSOA) working in reflection. Counterclockwise (S-shaped) and reverse (clockwise) bistability are observed in the output of the control and the signal beam respectively, as the power of the input control signal is increased. With this technique an optical signal can be set in either of the optical input wavelengths by appropriate choice of the powers of the input signals. The switching properties of the DFBSOA are studied experimentally as the applied bias current is increased from below to above threshold and for different levels of optical power in the signal beam and different wavelength detunings between both input signals. Higher on-off extinction ratios, wider bistable loops and lower input power requirements for switching are obtained when the DFBSOA is operated slightly above its threshold value

Productivity and convergence in European agriculture

In the paper we investigate relative productivity levels and decompose productivity change for European agriculture between 2004 and 2013. More specifically (1) we contribute to the debate whether agricultural Total Factor Productivity (TFP) has declined or not in the European Union (EU); (2) we compare the relative TFP level across EU member states and investigate the difference between 'old' member states (OMS, i.e. the EU-15) and 'new' member states (NMS) and (3) we test whether TFP is converging or not among member states. The empirical analysis applies the aggregate quantity framework developed in O'Donnell (2008), using country level panel data from the Economic Accounts for Agriculture for 23 EU member states. The results imply that TFP has slightly decreased in the EU over the analysed period; however there are significant differences in this respect between the OMS and NMS and across member states. Finally, our estimations support the productivity convergence hypothesis across the member states

Inefficiency in the German Mechanical Engineering Sector

This paper aims to examine the relative efficiency of German engineering firms using a sample of roughly 23,000 observations between 1995 and 2004. As these firms had been successful in the examination period in terms of output- and export-growth, it is expected that a majority of firms is operating quite efficiently and that the density of efficiency scores is skewed to the left. Moreover, as the German engineering industry is dominated by medium sized firms, the question arises whether these firms are the most efficient ones. Finally an increasing efficiency gap between size classes over time is important since that would be a signal for a structural problem within the industry. The analysis - using recently developed DEA methods like bootstrapping or outlier detection - contradicts the two first expectations. The firms proved to operate quite inefficiently with an overall mean of 0.69, and efficiency differs significantly with firm size whereas medium sized firms being on average the least efficient ones. When looking at changes in efficiency over time, we find a decreasing efficiency gap between size classes

Anchored enrichment dataset for true flies (order Diptera) reveals insights into the phylogeny of flower flies (family Syrphidae)

Background: Anchored hybrid enrichment is a form of next-generation sequencing that uses oligonucleotide probes to target conserved regions of the genome flanked by less conserved regions in order to acquire data useful for phylogenetic inference from a broad range of taxa. Once a probe kit is developed, anchored hybrid enrichment is superior to traditional PCR-based Sanger sequencing in terms of both the amount of genomic data that can be recovered and effective cost. Due to their incredibly diverse nature, importance as pollinators, and historical instability with regard to subfamilial and tribal classification, Syrphidae (flower flies or hoverflies) are an ideal candidate for anchored hybrid enrichment-based phylogenetics, especially since recent molecular phylogenies of the syrphids using only a few markers have resulted in highly unresolved topologies. Over 6200 syrphids are currently known and uncovering their phylogeny will help us to understand how these species have diversified, providing insight into an array of ecological processes, from the development of adult mimicry, the origin of adult migration, to pollination patterns and the evolution of larval resource utilization. Results: We present the first use of anchored hybrid enrichment in insect phylogenetics on a dataset containing 30 flower fly species from across all four subfamilies and 11 tribes out of 15. To produce a phylogenetic hypothesis, 559 loci were sampled to produce a final dataset containing 217,702 sites. We recovered a well resolved topology with bootstrap support values that were almost universally >95 %. The subfamily Eristalinae is recovered as paraphyletic, with the strongest support for this hypothesis to date. The ant predators in the Microdontinae are sister to all other syrphids. Syrphinae and Pipizinae are monophyletic and sister to each other. Larval predation on soft-bodied hemipterans evolved only once in this family. Conclusions: Anchored hybrid enrichment was successful in producing a robustly supported phylogenetic hypothesis for the syrphids. Subfamilial reconstruction is concordant with recent phylogenetic hypotheses, but with much higher support values. With the newly designed probe kit this analysis could be rapidly expanded with further sampling, opening the door to more comprehensive analyses targeting problem areas in syrphid phylogenetics and ecology.Peer reviewe

Phylogenetic congruence and ecological coherence in terrestrial Thaumarchaeota

This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. Acknowledgements We would like to thank Dr Robert Griffith/CEH for providing DNA from soil samples and Dr Anthony Travis for his help with BioLinux. Sequencing was performed in NERC platform in Liverpool. CG-R was funded by a NERC fellowship NE/J019151/1. CQ was funded by a MRC fellowship (MR/M50161X/1) as part of the cloud infrastructure for microbial genomics consortium (MR/L015080/1).Peer reviewedPublisher PD