Scale properties in data envelopment analysis

Recently there has been some discussion in the literature concerning the nature of scale properties in the Data Envelopment Model (DEA). It has been argued that DEA may not be able to provide reliable estimates of the optimal scale size. We argue in this paper that DEA is well suited to estimate optimal scale size, if DEA is augmented with two additional maintained hypotheses which imply that the DEA-frontier is consistent with smooth curves along rays in input and in output space that obey the Regular Ultra Passum (RUP) law (Frisch 1965). A necessary condition for a smooth curve passing through all vertices to obey the RUP-law is presented. If this condition is satisfied then upper and lower bounds for the marginal product at each vertex are presented. It is shown that any set of feasible marginal products will correspond to a smooth curve passing through all points with a monotonic decreasing scale elasticity. The proof is constructive in the sense that an estimator of the curve is provided with the desired properties. A typical DEA based return to scale analysis simply reports whether or not a DMU is at the optimal scale based on point estimates of scale efficiency. A contribution of this paper is that we provide a method which allows us to determine in what interval optimal scale is located.DEA; efficiency

Emerging Meta-Governance as a Regulation Framework for Public-Private Partnerships: An Examination of the European Union's Approach

This article extends previous research on public-private partnerships (PPPs), which has primarily been case study or national context oriented, by examining how these PPPs are regulated in the framework of the European Union (EU). While a number of partnership models have been identified in the academic literature, this study focuses on three significant types of PPP: the contract-PPP, the concession-PPP, and the institutional-PPP. Based on a notion of the EU as a meta-governance framework that guides, steers, and controls PPP activity at national, sector, and project level, the article draws a number of lessons on the EU’s role in regulating the formation phase of PPP. The research demonstrates that this meta-governance framework provides the EU with no direct regulations for the use of the PPP model in the 27 member states, but two sets of regulations which apply if a public authority decides to sign a PPP deal. As the EU hitherto has engaged in regulation of PPP at a somewhat abstract and conceptual level, national and local public administrations are given considerable room for manoeuvre to craft regulations and policies to support or hinder uptake of PPPs. More recently, however, the Commission has raised its stakes by launching a European Partnership Excellence Centre to support policy learning, the spread of best practice, and PPP expert networks

Public-Private Partnerships as Converging or Diverging Trends in Public Management? A Comparative Analysis of PPP Policy and Regulation in Denmark and Ireland

The utilization of the public-private partnership (PPP) model as a means of delivering various types of asset-based public services and infrastructure is often seen in academic research as part of a globally spread public management reform trend. This view is often suggested with reference to the staggering amount of attention and public money, which is now being dedicated to the formation of PPPs worldwide. This article, however, proceeds from the observation that if we look beyond the reports from a small handful of primarily Anglo-Saxon countries, which have so far attracted widespread attention in the PPP literature, we observe a much more divergent and heterogeneous pattern in various national governments’ policy and regulation for PPP and the amount of actually implemented PPP projects. By comparing the initiatives taken by the Irish government, which has embraced PPPs, with those of the Danish government, which has been PPP sceptic, the article draws on two in-depth country case studies to examine how and why PPPs developed so differently in the two countries. The research illustrates that whereas PPPs in Denmark have been subject to a loosely organized institutional framework with a number of fundamental policy and regulation issues being either unresolved or not very supportive to the uptake of PPPs, Ireland, on the other hand, now presides over one of the most ambitious PPP programs in the world, with major policy, regulation and procurement functions centralized within the Ministry of Finance and the Treasury. As research on PPPs continues to proliferate, this article illustrates that academic PPP literature would benefit from adopting a more explicit comparative focus to account for these significant comparative differences in national governments’ PPP approaches

Phylogeny of Triticeae (Poaceae) Based on Three Organelle Genes, Two Single-Copy Nuclear Genes, and Morphology

Triticeae are renowned for their complicated taxonomy, but their phylogeny is equally intricate and perplexing, and remains largely unresolved. Based on morphology and nucleotide sequences from two plastid genes (rbcL, rpoA), one mitochondrial gene (coxII), and two single-copy nuclear genes (DMC1, EF-G), the most comprehensive hypothesis (both with respect to taxa and data points) of the phylogeny of diploid Triticeae to date is presented. The incongruence length difference tests clearly indicate that the four logical data partitions (morphology and the three genome compartments) are mutually incongruent, except the mitochondrial and nuclear sequences. Nonetheless, a total evidence approach results in a highly resolved, strongly supported consensus tree, though partitioned Bremer support points to a high level of conflict among the individual data sets

How Many Loci Does it Take to DNA Barcode a Crocus?

BACKGROUND: DNA barcoding promises to revolutionize the way taxonomists work, facilitating species identification by using small, standardized portions of the genome as substitutes for morphology. The concept has gained considerable momentum in many animal groups, but the higher plant world has been largely recalcitrant to the effort. In plants, efforts are concentrated on various regions of the plastid genome, but no agreement exists as to what kinds of regions are ideal, though most researchers agree that more than one region is necessary. One reason for this discrepancy is differences in the tests that are used to evaluate the performance of the proposed regions. Most tests have been made in a floristic setting, where the genetic distance and therefore the level of variation of the regions between taxa is large, or in a limited set of congeneric species. METHODOLOGY AND PRINCIPAL FINDINGS: Here we present the first in-depth coverage of a large taxonomic group, all 86 known species (except two doubtful ones) of crocus. Even six average-sized barcode regions do not identify all crocus species. This is currently an unrealistic burden in a barcode context. Whereas most proposed regions work well in a floristic context, the majority will--as is the case in crocus--undoubtedly be less efficient in a taxonomic setting. However, a reasonable but less than perfect level of identification may be reached--even in a taxonomic context. CONCLUSIONS/SIGNIFICANCE: The time is ripe for selecting barcode regions in plants, and for prudent examination of their utility. Thus, there is no reason for the plant community to hold back the barcoding effort by continued search for the Holy Grail. We must acknowledge that an emerging system will be far from perfect, fraught with problems and work best in a floristic setting