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Collective dominance in competion law
Full text linkThis thesis analyses how competition law deals with the category of collective dominance. Collective dominance describes a market situation where more firms, by acting together as if they were a single entity, jointly exert market power. This phenomenon is relevant in the preventive control of mergers and in the repressive control of abuses of dominant position and it usually involves oligopolistic markets. The economic framework of my analysis is the Game theory. This thesis consists of three parts. In the first part, I analyse the evolution of collective dominance in the European competition law. In this exposition, I follow a chronological order, at the scope of highlighting the mutual influence between abuses of dominance and mergers. In the second part, I analyse how the US competition policy has approached the matter of oligopolistic parallelism. In this case, I distinguish ex post and ex ante control on tacit collusion, because the different theoretical framework, especially in terms of economic theories, which characterizes the preventive and repressive control on collusion, results in different antitrust policies. As a conclusion of parts 1 and 2, I compare the results obtained in the two systems and I seek to demonstrate that their relationship, with regard to collective dominance, is, at once, one of tension and overlap. In the third part, I propose a solution to deal with collective dominance. First of all, I remark the complexity of the category at issue and, for this reason, I define collective dominance in a conceptual and classificatory way. Then, I suggest addressing the matter of post-merger coordination by a three-step test, which focuses in the firms' ability to stably collude, on the convenience of colluding, and on the incapability of addressing the competitive concerns by the parties' commitments. In this scenario, prohibitions constitute an extreme solution. With regard to the abuses, I distinguish the case of collective dominance coming from the mere oligopolistic parallelism from the other sources. As for the latter, I critically analyses the relationship between articles 81 and 82 in the area of collective dominance; as for the first, I suggest bringing tacit collusion within the control of article 82, on the grounds of the objective notion of abuses. I also argue that the category of tacit collusion should also embrace the phenomenon of semi-collusion, when they leas to the same outcome. Finally, with regard to the possible remedies, I emphasize the role of injunctions in the case of anti-competitive oligopolistic parallelism, together with the possibility for competition authorities to impose monetary sanctions, whenever they find out culpable conducts
Dynamic software architectures for global computing system
Full text linkModern software systems have changed from isolated static
devices to highly interconnected machines that execute their
tasks in a cooperative and coordinated manner. Therefore, the structure and the behavior of these systems are dynamic with continuous changes. These systems are known as Global Computing Systems (GCSs) and they use services as fundamental elements for developing them. Software architectural models are intended to describe the structure and behavior of a system in terms of computational entities, their interactions and its composition patterns, so to reason about systems at more abstract level, disregarding implementation details. Since a GCS may change at run-time, Software Architecture (SA) models for them should be able to describe the changes of each system and to enact modifications during system execution.
Such models are generally referred to as Dynamic Software Architectures (DSAs), to emphasize that the SA evolves during run-time. Several recent research efforts have focused on the dynamic aspects of software architectures providing suitable models and techniques for handling the run-time modification of the structure of a system. A large number of heterogeneous proposals for addressing dynamic architectures at many different levels of abstractions have been provided, such as programmable, ad-hoc, self-healing and self-repairing among others. It is then important to have a clear picture of the relations among these proposals by formulating them into a uniform framework. When this work started there were many questions that arise. How can we represent architectures? How can we formalise architectural styles? How can we construct style conformant architectures? How can we model softwarearchitecture reconfigurations? How can we ensure style consistency?
How can we express and verify structural and behavioral
architectural properties? This thesis tries to answer
them. In particular it presents a formal-based process that will be used to model and verify Software Architectures that are dynamic. The principal aspects that we have considered in this work are:
a) formalisms used in the design of SA that are dynamic;
b) mechanisms to express and verify structural and behavioral properties that we expect to be satisfied by each SA configuration;
c) a complete tool-supported process able to integrate previous aspects.
These aspects are firstly illustrated over an explanatory example and then applied and validated over a real-world case study
Politics behind globalization: the influence of political and security variables on economic interdependence among States
Full text linkThe dissertation investigates the influence of domestic and international politics on economic interdependence among states in the age of globalization. On the one hand it aims at updating the studies on the influence of political variables on international trade taking into consideration the post-Cold War years. On the other hand it aims at expanding the operational definition of economic interdependence performing the first empirical of the influence of politics on bilateral flows of FDI. Through an extensive use of panel data analysis, I find that both domestic and international politics have a relevant impact on economic interdependence even in the context of globalization. However, none of the classic theories of international relations on the causes and consequences of interdependence can fully explain the current dynamics. The system is increasingly complex and the realist and liberal seem to work together accounting for different phenomena that happen contemporaneously
Ubi maior, ibi ius: assessing justice system reform in Afghanistan
Full text linkThis study analyses the reform of justice in Afghanistan which started in the wake of the US-led military intervention of 2001. In particular, it focuses on the role of international actors and their interaction with local stakeholders. The research addresses a number of issues, relating to the way justice system reform is practically carried out in Afghanistan. It also highlights some provisional results, together with problems and dilemmas encountered in the reform activities. The main objective of this study is to evaluate whether the success of justice
system reform in Afghanistan may be linked to any specific reason, feature or approach. The research has been conducted under a twofold approach, comprising both theoretical and practical phases. The former phase has
included the analysis of the relevant literature on the topic, drawing particular attention on several specific issues of interest (e.g. the development cooperation policies currently applied at international level, the ‘local ownership’ principle, the justice system in place in
Afghanistan, etc.). This theoretical phase has been enriched by a period of study at the Department of Peace Studies of the University of Bradford (UK), and by the organization of the Conference on the Rule of Law in Afghanistan in July 2007. On the other hand, the practical
phase has been characterized by a ‘learning by doing’ methodology, the author having served as a consultant to the Italian Development Cooperation Office in Kabul (Dec. 2007 – May 2008), working within the ‘Italian Justice Programme’. This research confirms that justice system reform in Afghanistan may succeed only if development programmes are implemented through a real multilateral approach, involving domestic authorities and other
relevant local stakeholders. Success is therefore linked to: limiting the political interests of donors (which should abandon the idea of gaining ‘political dividends’ from their assistance); establishing pooled financing mechanisms for the sector reform; restricting the use of
bilateral projects; improving the efficacy of technical and financial aid; and concentrating the attention on the ‘demand for justice’ at local level rather than on the traditional supply of financial and technical assistance
A perceptual learning model to discover the hierarchical latent structure of image collections
Full text linkBiology has been an unparalleled source of inspiration for the work of researchers in several scientific and engineering fields including computer vision. The starting point of this thesis is the neurophysiological properties of the human early visual system, in particular, the cortical mechanism that mediates learning by exploiting information about stimuli repetition. Repetition has long been considered a fundamental correlate of skill acquisition andmemory formation in biological aswell
as computational learning models. However, recent studies
have shown that biological neural networks have differentways of exploiting repetition in forming memory maps. The thesis focuses on a perceptual learning mechanism called repetition suppression, which exploits the temporal distribution of neural activations to drive an efficient neural allocation for a set of stimuli. This explores the neurophysiological hypothesis that repetition suppression serves as an unsupervised perceptual learning mechanism that can drive efficient memory formation by reducing the overall size of stimuli representation while strengthening the responses of the most selective neurons.
This interpretation of repetition is different from its traditional role in computational learning models mainly to induce convergence and reach training stability, without using this information to provide focus for the neural representations of the data.
The first part of the thesis introduces a novel computational model with repetition suppression, which forms an unsupervised competitive systemtermed CoRe, for Competitive Repetition-suppression learning. The model is applied to generalproblems in the fields of computational intelligence and machine learning. Particular emphasis is placed on validating the model as an effective tool for the unsupervised exploration of bio-medical data. In particular, it is shown that the repetition suppression mechanism efficiently addresses the issues of automatically estimating the number of clusters within the data, as well as filtering noise and irrelevant input components
in highly dimensional data, e.g. gene expression levels
from DNA Microarrays. The CoRe model produces relevance
estimates for the each covariate which is useful, for instance, to discover the best discriminating bio-markers.
The description of the model includes a theoretical analysis
using Huber’s robust statistics to show that the model is robust to outliers and noise in the data. The convergence properties of themodel also studied. It is shown that, besides its biological underpinning, the CoRe model has useful properties in terms of asymptotic behavior. By exploiting a kernel-based formulation for the CoRe learning error, a theoretically sound motivation is provided for the model’s ability to avoid local minima of its loss function. To do this a necessary and sufficient condition for global error minimization in vector quantization is generalized by extending it to distance metrics in generic Hilbert spaces. This leads to the derivation of a family of kernel-based algorithms that address the local minima issue of unsupervised vector quantization in a principled way.
The experimental results show that the algorithm can achieve
a consistent performance gain compared with state-of-the-art
learning vector quantizers, while retaining a lower computational complexity (linear with respect to the dataset size).
Bridging the gap between the low level representation of the
visual content and the underlying high-level semantics is a
major research issue of current interest. The second part of
the thesis focuses on this problem by introducing a hierarchical and multi-resolution approach to visual content understanding. On a spatial level, CoRe learning is used to pool together the local visual patches by organizing them into perceptually meaningful intermediate structures. On the semantical level, it provides an extension of the probabilistic Latent Semantic Analysis (pLSA) model that allows discovery and organization of the visual topics into a hierarchy of aspects.
The proposed hierarchical pLSA model is shown to effectively
address the unsupervised discovery of relevant visual
classes from pictorial collections, at the same time learning to segment the image regions containing the discovered classes. Furthermore, by drawing on a recent pLSA-based image annotation system, the hierarchical pLSA model is extended to process and representmulti-modal collections comprising textual and visual data. The results of the experimental evaluation show that the proposed model learns to attach textual labels (available only at the level of the whole image) to the discovered image regions, while increasing the precision/ recall performance with respect to flat, pLSA annotation model
Essays on the effects of flexibility on labour market outcome
Full text linkThe thesis is structured in three articles which develop an analysis focused on the effects of labour market regulation on the labour market outcome and country economic performance. The first paper makes a review of literature by supporting the "OECD-IMF orthodoxy" according to which the rigidities imposed by labour market institutions are crucial determinants to explain European unemployment. Many works have been published which support this view. While these studies have become increasingly complex, the empirical results do not appear to be robust since they are highly sensitive to the nature of variables, the time period, and the econometric methods applied. Various reasons explain the adherence to this orthodoxy: the existence of priors, poor data on labour market institutions, as well as unsuitable econometric techniques. Considering that additional cross-country analysis will not be decisive to improve our understanding of labour market institutions, this paper suggests new investigations which rely on time-seriescross-section (TSCS) techniques, micro-analysis of firms and workers, as well as human subject and artificial experiments. The second paper delves into the relationship existing between labour market flexibility - epitomized by the proportion of temporary and part-time workers - and companies’ ability to innovate- as measured by the percentage of new products in total sales. Even though it is an important issue affecting a country economic growth, the analysis of the flexibility effects
on companies’ innovativeness is almost neglected in current
literature. On the one hand, ’more flexibility’ (i.e. a higher labour turnover) might foster firms’ innovation potential. Beside having (potential) wage savings effects, a larger inflow of new staff may enrich the pool of companies’ innovative ideas. On the other hand, greater work flexibility may have some drawbacks: steadily high rates of people entering and leaving firms may reduce social cohesion and trust, as well as increase the probability of opportunistic behaviour. Results suggest
that a higher percentage of internal flexibility is associated with greater propensity to innovate, especially in high-tech firms. In line with the 1999/70/EC European directive, these results also suggest that fixed-term contracts (external flexibility) might be useful in periods of extraordinary corporate activity, but can have disadvantages for firms innovativeness and productivity if
improperly used during normal activity. Finally, the third paper refers to one of the most attractive model for policymakers in Europe: the flexicurity model that combines elements of flexibility in labour markets with income and employment security for workers. Although common principles
might drive labour market reforms, flexicurity should take up different forms from country to country. The aim of this work is investigate which is the suitable pathway for Italy
and identify the advantages and risks of adopting lexicurity
policies. In the first part, the paper examines flexicurity in Denmark, one of the leading country in this field, and then focuses on Italian labour market only. In particular, on the basis of an experimental analysis, the second part investigates the possibility for Italy to follow the first European flexicurity pathway which - in the case of countries with segmented labour markets - suggests to rely on contractual arrangements to distribute flexibility and security more evenly across the workforce. Unlike other experimental analysis, in this case the level of unemployment is determined endogenously and the level of
efforts made is observable with a certain degree of uncertainty. This feature allows to study the interactions of labour market regulation and firms’ employment policy in determining the unemployment level. Results suggest that - especially in countries such as Italy, where there is limited scope for increasing spending - these contractual arrangements can improve the situation both for workers and companies
Essays on the real effects of banking development and concentration
Full text linkThis thesis consists of three essays on the impact of banking development and concentration on the real economy. By looking at three specific mechanisms, this work supports the hypothesis that access to finance may be a barrier to entry and exit of firms. Furthermore, it provides empirical evidence of non-linearity in the relationship between banking market structure and the real economy. The three essays adopt the Rajan-Zingales (1998) methodology, which
is especially useful for establishing a causal relationship between finance and real sector performance as well as for overcoming potential endogeneity problems. The first essay investigates the relationship between bank concentration
and the real economy by analyzing the number and average size of firms in manufacturing industries in two samples of countries with differing levels of economic development. The main finding is that in developed countries a higher bank concentration is associated with a lower number of firms, of bigger size, while in developing countries
this relationship does not seem significant. The second essay analyzes the effect of bank concentration on firm
demography, conditional on the depth of credit markets. The empirical evidence on a sample of EU countries shows negative effects of bank concentration on firm demography when domestic the size of banking market is sufficiently large. This suggests that bank concentration in itself is not a barrier to entry and exit of firms. The third essay extends a recent cross-country study by Coricelli and
Roland (2008) on the asymmetric effects of banking development on real economy performance, distinguishing periods of economic expansion from declines. Using data for Italy, this essay examines the issue at regional level and shows that more developed local credit markets are associated with lower declines in firm net entry rates
Tools and models for high level parallel and Grid programming
Full text linkWhen algorithmic skeletons were first introduced by Cole in
late 1980 (50) the idea had an almost immediate success. The
skeletal approach has been proved to be effective when application algorithms can be expressed in terms of skeletons composition. However, despite both their effectiveness and the progress made in skeletal systems design and implementation, algorithmic skeletons remain absent from mainstream practice. Cole and other researchers, respectively in (51) and (19), focused the problem. They recognized the issues affecting
skeletal systems and stated a set of principles that have
to be tackled in order to make them more effective and to
take skeletal programming into the parallel mainstream. In
this thesis we propose tools and models for addressing some
among the skeletal programming environments issues. We
describe three novel approaches aimed at enhancing skeletons
based systems from different angles. First, we present a model we conceived that allows algorithmic skeletons customization exploiting the macro data-flow abstraction. Then we present two results about the exploitation of metaprogramming techniques for the run-time generation and optimization of macro data-flow graphs. In particular, we show how to generate and how to optimize macro data-flow graphs accordingly both to programmers provided non-functional requirements and to execution platform features. The last result we present are the Behavioural Skeletons, an approach aimed at addressing the limitations of skeletal programming environments when used for the development of component-based Grid applications.
We validated all the approaches conducting several test,
performed exploiting a set of tools we developed
Theoretical and experimental economic analysis of collusion
Full text linkThis research project consists in a theoretical and experimental study of oligopolistic markets. I believe that an experimental approach to this subject might help to understand the interplay of the many different factors that affect firms behavior in this context, and to analyze problems
which theory does not provide a clearcut answer to. My project develops into two main parts: the first concern how firms can learn to collude tacitly, the second studies deterrence of explicit collusion