3,554 research outputs found
Merger Simulation in Competition Policy: A Survey
Advances in competition economics as well as in computational and empirical methods have offered the scope for the employment of merger simulation models in merger control procedures during the past almost 15 years. Merger simulation is, nevertheless, still a very young and innovative instrument of antitrust and, therefore, its ‘technical’ potential is far from being comprehensively exploited and teething problems in its practical use in the antitrust environment prevail. We provide a classification of state-of-the-art merger simulation models and review their previous employment in merger cases as well as the problems and limitations currently associated with their use in merger control. In summary, merger simulation models represent an important and valuable extension of the toolbox of merger policy. However, they do not qualify as a magic bullet and must be combined with other, more traditional instruments of competition policy in order to comprehensively unfold its beneficial effects. The authors thank Ulrich Schwalbe, Wolfgang Kerber, Arndt Christiansen and Niels Vestergaard for valuable comments on earlier versions of the paper, the participants of the 30th Hohenheimer Oberseminar (Nuernberg, April 2008) for helpful discussion, and Barbara Güldenring for valuable editorial assistance.Merger simulation, merger control, antitrust, oligopoly theory, auction models, mergers & acquisitions
Models of public-private partnerships in megaprojects: the Spanish case
This article provides a
literature review of PPP Models, where the clarification of this current
confusion and ambiguity constitute the fundamental issue addressed
by our research. The systematization of the PPP models is performed by
applying six classification criteria based on organizational and financial
aspects and focused on the Spanish experience. Additionally, a comparative
study of the various schemes applied in European countries is
carried out, whereby the concession model implemented successfully
in Spain is studied in greater detail. To this end, a megaproject, the first
metro line of Seville (Spain) forms the basis of a case-study. When the
megaproject is viable through user fees, the public sector can use PPPs
to defer payments and as a way to control their deficits and debt without
cutting investments in infrastructures and public services. Nevertheless,
certain drawbacks should be borne in mind, such as the expenditure
commitments of future budgets, the higher cost of private funding, and
the necessity for transparency and accountability of PPP contractual
arrangements to be improved. Therefore, the aim of this article is to
analyze the various forms of PPPs in megaprojects in order to determine
the potential efficiency gains that can be achieved in the implementation
of these models
Improving bankruptcy prediction in micro-entities by using nonlinear effects and non-financial variables
The use of non-parametric methodologies, the introduction of non-financial variables,
and the development of models geared towards the homogeneous characteristics of
corporate sub-populations have recently experienced a surge of interest in the bankruptcy
literature. However, no research on default prediction has yet focused on micro-entities
(MEs), despite such firms’ importance in the global economy. This paper builds the first
bankruptcy model especially designed for MEs by using a wide set of accounts from 1999
to 2008 and applying artificial neural networks (ANNs). Our findings show that ANNs
outperform the traditional logistic regression (LR) models. In addition, we also report
that, thanks to the introduction of non-financial predictors related to age, the delay
in filing accounts, legal action by creditors to recover unpaid debts, and the ownership
features of the company, the improvement with respect to the use of solely financial
information is 3.6%, which is even higher than the improvement that involves the use
of the best ANN (2.6%)
Hybrid model using logit and nonparametric methods for predicting micro-entity failure
Following the calls from literature on bankruptcy, a parsimonious hybrid bankruptcy model is developed in this paper
by combining parametric and non-parametric approaches.To this end, the variables with the highest predictive power to
detect bankruptcy are selected using logistic regression (LR). Subsequently, alternative non-parametric methods
(Multilayer Perceptron, Rough Set, and Classification-Regression Trees) are applied, in turn, to firms classified as
either “bankrupt” or “not bankrupt”. Our findings show that hybrid models, particularly those combining LR and
Multilayer Perceptron, offer better accuracy performance and interpretability and converge faster than each method
implemented in isolation. Moreover, the authors demonstrate that the introduction of non-financial and macroeconomic
variables complement financial ratios for bankruptcy prediction
Kernel alternatives to aproximate operational severity distribution: an empirical application
The estimation of severity loss distribution is one the main topic in operational
risk estimation. Numerous parametric estimations have been suggested
although very few work for both high frequency small losses and low frequency
big losses. In this paper several estimation are explored. The good performance
of the double transformation kernel estimation in the context of operational risk
severity is worthy of a special mention. This method is based on the work of
Bolancé and Guillén (2009), it was initially proposed in the context of the cost of
claims insurance, and it means an advance in operational risk research
Hybrid analog-digital transmit beamforming for spectrum sharing backhaul networks
© 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes,creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.This paper deals with the problem of analog-digital transmit beamforming under spectrum sharing constraints for backhaul systems. In contrast to fully digital designs, where the spatial processing is done at baseband unit with all the flexible computational resources of digital processors, analog-digital beamforming schemes require that certain processing is done through analog components, such as phase-shifters or switches. These analog components do not have the same processing flexibility as the digital processor, but on the other hand, they can substantially reduce the cost and complexity of the beamforming solution. This paper presents the joint optimization of the analog and digital parts, which results in a nonconvex, NP-hard, and coupled problem. In order to solve it, an alternating optimization with a penalized convex-concave method is proposed. According to the simulation results, this novel iterative procedure is able to find a solution that behaves close to the fully digital beamforming upper bound scheme.Peer ReviewedPostprint (author's final draft
The financial performance of an innovative megaproject
The financial structure of megaprojects, known in the literature as project finance, is characterized by the creation of a legally
independent project company financed with a concentrated equity ownership and a high level of non-recourse debt. Research in
this field may yield new ideas and theories about the existing theoretical framework on capital structure, stakeholder
management and risk management. A case-study is analyzed in this paper: the financial performance of the first metro line in
Seville (Spain). In spite of previous cost overruns in the construction stage, the present operation stage is considered successful
from the point of view of social and financial profitability, whereby the risks have been theoretically transferred to stakeholders,
as defined by Value for Money considerations.
The objective of this study involves: first to determine whether this megaproject meets the expectations for which it was created
in terms of hope of return of the shareholders, and the expectations of the economic and financial feasibility under a change of
subsidy policies; and secondly to determine whether the conditions remain for not including the investment as public debt. This
issue is crucial in a budgetary constraint context for the planning of future metro lines. By taking this first experience into
account, this article also provides information for potential participants in the projects of the new metro lines, which are
currently in the planning stage
A Comparison of classification/regression trees and logistic regression in failure models
The use of non-parametric statistical methods, the development of models geared towards the homogeneous characteristics of
corporate sub-populations, and the introduction of non-financial variables, are three main issues analysed in this paper. This
study compares the predictive performance of a non-parametric methodology, namelyClassification/Regression Trees (CART),
against traditional logistic regression (LR) by employing a vast set of matched-pair accounts of the smallest enterprises, known as
micro-entities,from the United Kingdom for the period 1999 to 2008 that includes financial, non-financial, and macroeconomic
variables. Our findings show that CART outperforms the standard approach in the literature, LR
Global anomalies in Chiral Lattice Gauge Theory
As first realized by Witten an SU(2) gauge theory coupled to a single Weyl
fermion suffers from a global anomaly. This problem is addressed here in the
context of the recent developments on chiral gauge theories on the lattice. We
find Witten's anomaly manifests in the impossibility of defining globally a
fermion measure that reproduces the proper continuum limit. Moreover, following
Witten's original argument, we check numerically the crossing of the lowest
eigenvalues of Neuberger's operator along a path connecting two gauge fields
that differ by a topologically non-trivial gauge transformation.Comment: LATTICE99(Chiral Gauge Theories) - 6 pages, 2 figure
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