Essay 1: An Examination of the Efficiency, Foreclosure, and Collusion Rationales for Vertical Takeovers We investigate the efficiency, foreclosure, and collusion rationales for vertical integration using a large sample of vertical takeovers. The efficiency rationale posits that vertical integration prevents future holdup between non-integrated suppliers and customers. In contrast, the foreclosure and collusion rationales suggest that vertical integration harms competition. To distinguish between these hypotheses, we examine the wealth effects of the merging firms, acquirer rivals, target rivals, and corporate customers on announcement of vertical takeovers. Our univariate and cross-sectional results suggest that firms alter their vertical boundaries in a manner that is consistent with the efficiency rationale. Our tests do not find evidence supportive of the anti-competitive rationales for vertical integration. Essay 2: Determinants of Firm Vertical Boundaries and Implications for Internal Capital Markets In this paper, we investigate the determinants of vertical relatedness between business segments of multi-segment firms and how vertical relatedness affects the internal allocation of capital. Consistent with theory, we observe a higher degree of vertical relatedness between segments in environments likely to involve contracting problems. Further, there is a greater tendency for investments to flow towards segments with better investment opportunities as the degree of vertical relatedness between business segments in the firm increases. This indicates that internal capital markets function better in the presence of significant vertical relatedness between segments. This finding supports the Stein (1997) model, which suggests that the headquarters is able to do a better job of “winner-picking” when firms operate in related lines of businesses.

<p>Black Economic Empowerment (BEE) has been a topic of discussion since the dawn of democracy in April 1994. Due to the entrenched inequalities of the past, economic empowerment is very important for the economic growth of the majority of South Africa&rsquo / s citizens. However, significant economic enrichment of black people has not been made, despite, economic success, legislation, state policies and programme interventions. This economic growth is to be realised through the use of preferential procurement as a policy tool for BEE. Whilst sufficient legislation has been enacted to regulate preferential procurement, to favour black people, much still seems to be lacking in the enforcement of the laws in public procurement. Central to the challenges of preferential procurement is the disharmony between the Framework legislation governing preferential procurement and BEE. This discord has seen two visions being followed for preferential procurement / the Procurement Act refers to the beneficiaries of BEE as historically disadvantaged individuals (HDI / s) and the goals for BEE are measured through specific goals which promotes narrow empowerment / the BBBEE Act on the other hand defines black people as the recipients of BEE and through the BEE Codes broad-based empowerment is promoted through seven core elements. This congruency has not served the promotion of preferential procurement, it has created a hindrance that frustrates economic growth for those it is intended. The other quandary that undermines the success of preferential procurement is willful practices engaged by both tenderers and public officials / skills deficiency in the adjudication of tenders and self-interest. The success of BEE through preferential procurement is dependent on a coherently legislated procurement environment fortified by perceptive public officials. The objective of this thesis is to analyse the impact of these challenges on the success of preferential procurement. The study will highlight the main practices that defeat the use of preferential procurement. This will include an analysis of the various legislation and the amendments thereto. In addition the enquiry will examine the proficiency of public officials in the adjudication of public tendering. Recommendations for a successful preferential public procurement environment will be made. The proposed thesis will utilise, inter alia, relevant legislation, case law, theses, journals, books and policy documents.</p>

Recently, the American Association of State Highway and Transportation Officials (AASHTO) indicated lack of competition and single-bid contracts in asphalt paving as a major issue facing state transportation departments. Single-bid contracts indicate a lack of competition which increases costs to state and local governments. During the period from 2005-2007 in Kentucky, 42 percent of all bids were awarded with only one firm bidding on the project. Of the asphalt paving jobs, 63 percent of those jobs were awarded to a single bidder. The analysis of this dissertation focuses on detecting tacit collusion in asphalt paving jobs in Kentucky. A focal point enables firms to coordinate bids and engage in a tit-for-tat strategy where they refuse to bid in each other’s counties. In this case the focal point is the county boundaries. Two factors contribute to the ability of firms to use county boundaries to coordinate bids. The first factor is that the political county boundaries form relatively small counties which allow a firm’s service area to cover multiple counties. The firms are able to claim counties and service the projects in those counties. The second factor is that a majority of asphalt projects which the Kentucky Transportation Cabinet puts up for bidding are exclusive to a specific county. This allows firms to know whether a project falls in a county within their bidding territory. Each county and firm in each of the 12 Kentucky Transportation Cabinet geographic districts was analyzed to see if there was evidence of bid coordination. The result is that in 94 out of 120 counties there was evidence of bid coordination or tacit collusion with increases in bid levels. There is evidence that 25 of the 31 Kentucky asphalt paving firms refuse to bid against their rivals in their rival’s territories. This refusal by firms to bid against each other resulted in single-bid contracts that were $70,595,466.09 above the competitive level.

Submitted by Seiji Fetter (seijifetter@gmail.com) on 2012-03-25T15:05:42Z No. of bitstreams: 1 seijikf dissertacao final.pdf: 455320 bytes, checksum: 36d1a9b7fd17769fb9a735a6e3ef4c8c (MD5) / Approved for entry into archive by Gisele Isaura Hannickel (gisele.hannickel@fgv.br) on 2012-03-26T12:40:27Z (GMT) No. of bitstreams: 1 seijikf dissertacao final.pdf: 455320 bytes, checksum: 36d1a9b7fd17769fb9a735a6e3ef4c8c (MD5) / Made available in DSpace on 2012-03-26T12:55:13Z (GMT). No. of bitstreams: 1 seijikf dissertacao final.pdf: 455320 bytes, checksum: 36d1a9b7fd17769fb9a735a6e3ef4c8c (MD5) Previous issue date: 2012-03-05 / Modelos teóricos de colusão tácita podem fornecer predições sobre preços ou outras variáveis estratégicas que permitam a detecção de conduta anticompetitiva. Esses marcadores de colusão geram hipóteses testáveis sobre o comportamento cíclico dos preços, sua dispersão entre concorrentes e sua variabilidade temporal. Utilizando dados municipais mensais para preços e custos da gasolina, regressões de painel dinâmico em forma reduzida são realizadas para averiguar a aderência empírica desses marcadores. Os efeitos são identificados comparando com 10 municípios que tiveram cartéis operando no varejo de combustíveis. Os resultados corroboraram as predições de preços anticíclicos e redução da dispersão dos preços, ainda que com ressalvas. Porém, não se encontrou evidências de aumento de volatilidade nos preços induzidos por choques adversos de demanda, que pretende capturar uma maior frequência de guerras de preços. A redução da volatilidade dos preços é parcialmente confirmada. / Theoretic models of tacit collusion may offer predictions over prices or other strategic variables that allow for the detection of anticompetitive conduct. These collusion markers generate testable implications on the cyclical movement of prices, its dispersion and its time series variability. Using municipal monthly data of gasoline prices and costs, reduced-form dynamic panel regressions are employed to assess the empirical adherence of these markers. The effects are identified through comparison against 10 municipalities, which exhibited episodes of cartelization. The results point to some evidence of countercyclical pricing and price dispersion reduction. However, no evidence if found for price wars, measured through increased price volatility due to adverse demand shocks. The prediction of price volatility reduction is partially sustained.

[pt] Pesquisar preços pode ser custoso para os consumidores. Este artigo investiga os efeitos de busca na formação de conluio por parte das firmas. Para identificar tais efeitos, constrói-se um jogo repetido no qual os consumidores pesquisam preços seqüencialmente e as firmas competem por preços no jogo estático. Claramente, identificam-se dois efeitos distintos, por um lado, mais busca, i.e. mais consumidores pesquisando preços ou um menor custo de busca, facilita a formação de conluio, pois as firmas sustentam punições críveis mais severas. Por outro lado, mais busca dificulta a formação de conluio à medida que os desvios do conluio se tornam mais lucrativos. / [en] This paper investigates, through a theoretical approach, search effects on collusion. In order to identify these effects, we consider an infinitely repeated game; in the stage game, consumers search for prices sequentially and firms set price simultaneously. We clearly identify two different search effects on collusion; on the one hand, it facilitates collusion as the punishment payoff is lower. On the other hand, it makes collusion more difficult, since deviations are more profitable.

Sistemas online como Facebook, Twitter, Digg, e comunidades BitTorrent (entre vários outros) oferecem um processo leve para a obtenção de identidades (por exemplo, confirmar um endereço de e-mail válido; os requisitos podem variar dependendo do sistema), de modo que os usuários possam cadastrar-se facilmente nos mesmos. Tal conveniência vem com um preço, no entanto: com um pequeno esforço, um atacante pode obter uma grande quantidade de contas falsas (ataque Sybil), e utilizá-las para executar atividades maliciosas (que possam prejudicar os usuários legítimos) ou obter vantagens indevidas. É extremamente desafiador (senão impossível) desenvolver uma única solução de gerenciamento de identidades que seja ao mesmo tempo capaz de oferecer suporte a uma variedade de usuários usando dispositivos heterogêneos e adequada para uma diversidade de ambientes (por exemplo, sistemas distribuídos de larga escala, Internet das Coisas, e Internet do Futuro). Como consequência, a comunidade de pesquisa tem focado no projeto de soluções de gerenciamento de identidades customizadas, em cenários com um conjunto bem definido de propósitos, requisitos e limitações. Nesta tese, abordamos o problema de contas falsas em sistemas distribuídos de larga escala. Mais especificamente, nos concentramos em sistemas baseados no paradigma para- par e que podem acomodar esquemas de gerenciamento de identidades leves e de longo prazo (ex., sistemas de compartilhamento de arquivos e de live streaming, sistemas de detecção de intrusão colaborativos, entre outros); leves porque os usuários devem obter identidades sem precisar fornecer “provas de identidade” (ex., passaporte) e/ou pagar taxas; e longo prazo porque os usuários devem ser capazes de manter suas identidades (ex., através de renovação) por um período indefinido. Nosso principal objetivo é propor um arcabouço para precificar adaptativamente as solicitações de identidades como uma abordagem para conter ataques Sybil. A ideia chave é estimar um grau de confiança para as solicitações de identidades, calculada como função do número de identidades já concedidas em um dado período, considerando a origem dessas solicitações. Nossa abordagem baseia-se em prova de trabalho e usa desafios criptográficos como um recurso para conter atacantes. Nesta tese, nós também concentramos esforços na reformulação dos desafios tradicionais, de modo a torná-los “verdes” e “´uteis”. Os resultados obtidos via simulação e experimentação mostraram a viabilidade técnica de usar desafios verdes e ´uteis para o gerenciamento de identidades. Mais importante, eles mostraram que caracterizar as solicitações de identidades com base na origem das mesmas constitui uma abordagem promissora para lidar com a redução substancial da disseminação de contas falsas. / Online systems such as Facebook, Twitter, Digg, and BitTorrent communities (among various others) offer a lightweight process for obtaining identities (e.g., confirming a valid e-mail address; the actual requirements may vary depending on the system), so that users can easily join them. Such convenience comes with a price, however: with minimum effort, an attacker can obtain a horde of fake accounts (Sybil attack), and use them to either perform malicious activities (that might harm legitimate users) or obtain unfair benefits. It is extremely challenging (if not impossible) to devise a single identity management solution at the same time able to support a variety of end-users using heterogeneous devices, and suitable for a multitude of environments (e.g., large-scale distributed systems, Internet-of-Things, and Future Internet). As a consequence, the research community has focused on the design of system-specific identity management solutions, in scenarios having a well-defined set of purposes, requirements, and constraints. In this thesis, we approach the issue of fake accounts in large-scale, distributed systems. More specifically, we target systems based on the peer-to-peer paradigm and that can accommodate lightweight, long-term identity management schemes (e.g., file sharing and live streaming networks, collaborative intrusion detection systems, among others); lightweight because users should obtain identities without being required to provide “proof of identity” (e.g., passport) and/or pay taxes; and long-term because users should be able to maintain their identities (e.g., through renewal) for an indefinite period. Our main objective is to propose a framework for adaptively pricing identity requests as an approach to limit Sybil attacks. The key idea is to estimate a trust score for identity requests, calculated as a as function of the number of identities already granted in a given period, and considering their source of origin. Our approach relies on proof of work, and uses cryptographic puzzles as a resource to restrain attackers. In this thesis, we also concentrate on reshaping traditional puzzles, in order to make them “green” and “useful”. The results obtained through simulation and experimentation have shown the feasibility of using green and useful puzzles for identity management. More importantly, they have shown that profiling identity requests based on their source of origin constitutes a promising approach to tackle the dissemination of fake accounts.

Sistemas online como Facebook, Twitter, Digg, e comunidades BitTorrent (entre vários outros) oferecem um processo leve para a obtenção de identidades (por exemplo, confirmar um endereço de e-mail válido; os requisitos podem variar dependendo do sistema), de modo que os usuários possam cadastrar-se facilmente nos mesmos. Tal conveniência vem com um preço, no entanto: com um pequeno esforço, um atacante pode obter uma grande quantidade de contas falsas (ataque Sybil), e utilizá-las para executar atividades maliciosas (que possam prejudicar os usuários legítimos) ou obter vantagens indevidas. É extremamente desafiador (senão impossível) desenvolver uma única solução de gerenciamento de identidades que seja ao mesmo tempo capaz de oferecer suporte a uma variedade de usuários usando dispositivos heterogêneos e adequada para uma diversidade de ambientes (por exemplo, sistemas distribuídos de larga escala, Internet das Coisas, e Internet do Futuro). Como consequência, a comunidade de pesquisa tem focado no projeto de soluções de gerenciamento de identidades customizadas, em cenários com um conjunto bem definido de propósitos, requisitos e limitações. Nesta tese, abordamos o problema de contas falsas em sistemas distribuídos de larga escala. Mais especificamente, nos concentramos em sistemas baseados no paradigma para- par e que podem acomodar esquemas de gerenciamento de identidades leves e de longo prazo (ex., sistemas de compartilhamento de arquivos e de live streaming, sistemas de detecção de intrusão colaborativos, entre outros); leves porque os usuários devem obter identidades sem precisar fornecer “provas de identidade” (ex., passaporte) e/ou pagar taxas; e longo prazo porque os usuários devem ser capazes de manter suas identidades (ex., através de renovação) por um período indefinido. Nosso principal objetivo é propor um arcabouço para precificar adaptativamente as solicitações de identidades como uma abordagem para conter ataques Sybil. A ideia chave é estimar um grau de confiança para as solicitações de identidades, calculada como função do número de identidades já concedidas em um dado período, considerando a origem dessas solicitações. Nossa abordagem baseia-se em prova de trabalho e usa desafios criptográficos como um recurso para conter atacantes. Nesta tese, nós também concentramos esforços na reformulação dos desafios tradicionais, de modo a torná-los “verdes” e “´uteis”. Os resultados obtidos via simulação e experimentação mostraram a viabilidade técnica de usar desafios verdes e ´uteis para o gerenciamento de identidades. Mais importante, eles mostraram que caracterizar as solicitações de identidades com base na origem das mesmas constitui uma abordagem promissora para lidar com a redução substancial da disseminação de contas falsas. / Online systems such as Facebook, Twitter, Digg, and BitTorrent communities (among various others) offer a lightweight process for obtaining identities (e.g., confirming a valid e-mail address; the actual requirements may vary depending on the system), so that users can easily join them. Such convenience comes with a price, however: with minimum effort, an attacker can obtain a horde of fake accounts (Sybil attack), and use them to either perform malicious activities (that might harm legitimate users) or obtain unfair benefits. It is extremely challenging (if not impossible) to devise a single identity management solution at the same time able to support a variety of end-users using heterogeneous devices, and suitable for a multitude of environments (e.g., large-scale distributed systems, Internet-of-Things, and Future Internet). As a consequence, the research community has focused on the design of system-specific identity management solutions, in scenarios having a well-defined set of purposes, requirements, and constraints. In this thesis, we approach the issue of fake accounts in large-scale, distributed systems. More specifically, we target systems based on the peer-to-peer paradigm and that can accommodate lightweight, long-term identity management schemes (e.g., file sharing and live streaming networks, collaborative intrusion detection systems, among others); lightweight because users should obtain identities without being required to provide “proof of identity” (e.g., passport) and/or pay taxes; and long-term because users should be able to maintain their identities (e.g., through renewal) for an indefinite period. Our main objective is to propose a framework for adaptively pricing identity requests as an approach to limit Sybil attacks. The key idea is to estimate a trust score for identity requests, calculated as a as function of the number of identities already granted in a given period, and considering their source of origin. Our approach relies on proof of work, and uses cryptographic puzzles as a resource to restrain attackers. In this thesis, we also concentrate on reshaping traditional puzzles, in order to make them “green” and “useful”. The results obtained through simulation and experimentation have shown the feasibility of using green and useful puzzles for identity management. More importantly, they have shown that profiling identity requests based on their source of origin constitutes a promising approach to tackle the dissemination of fake accounts.

The State delegates the provision of an important number of services of general interest for society, and the State delegates them to private economic operators. However, in these circumstances the need for regulation in order to achieve allocative efficiency underlies as a duty of the State.In this article, the author presents how the criminal offence of collusion is a way of regulatory capture, and how it brings along negative consequences for the social welfare and progress. The author also reaches a conclusion concerning which is the legal right protected with the aforementioned crime. / El Estado delega la prestación de una serie de servicios de interés general para la sociedad en agentes económicos privados. Sin embargo, en estas circunstancias subyace como deber del Estado la necesidad de regulación en aras de conseguir eficiencia asignativa.En el presente artículo, el autor expone cómo el delito de colusión es una forma de captura del regulador, y cómo ello trae consigo consecuencias negativas para el bienestar y progreso social, además de presentar cuál es el bien jurídico que se protege en el mencionado delito.

Sistemas online como Facebook, Twitter, Digg, e comunidades BitTorrent (entre vários outros) oferecem um processo leve para a obtenção de identidades (por exemplo, confirmar um endereço de e-mail válido; os requisitos podem variar dependendo do sistema), de modo que os usuários possam cadastrar-se facilmente nos mesmos. Tal conveniência vem com um preço, no entanto: com um pequeno esforço, um atacante pode obter uma grande quantidade de contas falsas (ataque Sybil), e utilizá-las para executar atividades maliciosas (que possam prejudicar os usuários legítimos) ou obter vantagens indevidas. É extremamente desafiador (senão impossível) desenvolver uma única solução de gerenciamento de identidades que seja ao mesmo tempo capaz de oferecer suporte a uma variedade de usuários usando dispositivos heterogêneos e adequada para uma diversidade de ambientes (por exemplo, sistemas distribuídos de larga escala, Internet das Coisas, e Internet do Futuro). Como consequência, a comunidade de pesquisa tem focado no projeto de soluções de gerenciamento de identidades customizadas, em cenários com um conjunto bem definido de propósitos, requisitos e limitações. Nesta tese, abordamos o problema de contas falsas em sistemas distribuídos de larga escala. Mais especificamente, nos concentramos em sistemas baseados no paradigma para- par e que podem acomodar esquemas de gerenciamento de identidades leves e de longo prazo (ex., sistemas de compartilhamento de arquivos e de live streaming, sistemas de detecção de intrusão colaborativos, entre outros); leves porque os usuários devem obter identidades sem precisar fornecer “provas de identidade” (ex., passaporte) e/ou pagar taxas; e longo prazo porque os usuários devem ser capazes de manter suas identidades (ex., através de renovação) por um período indefinido. Nosso principal objetivo é propor um arcabouço para precificar adaptativamente as solicitações de identidades como uma abordagem para conter ataques Sybil. A ideia chave é estimar um grau de confiança para as solicitações de identidades, calculada como função do número de identidades já concedidas em um dado período, considerando a origem dessas solicitações. Nossa abordagem baseia-se em prova de trabalho e usa desafios criptográficos como um recurso para conter atacantes. Nesta tese, nós também concentramos esforços na reformulação dos desafios tradicionais, de modo a torná-los “verdes” e “´uteis”. Os resultados obtidos via simulação e experimentação mostraram a viabilidade técnica de usar desafios verdes e ´uteis para o gerenciamento de identidades. Mais importante, eles mostraram que caracterizar as solicitações de identidades com base na origem das mesmas constitui uma abordagem promissora para lidar com a redução substancial da disseminação de contas falsas. / Online systems such as Facebook, Twitter, Digg, and BitTorrent communities (among various others) offer a lightweight process for obtaining identities (e.g., confirming a valid e-mail address; the actual requirements may vary depending on the system), so that users can easily join them. Such convenience comes with a price, however: with minimum effort, an attacker can obtain a horde of fake accounts (Sybil attack), and use them to either perform malicious activities (that might harm legitimate users) or obtain unfair benefits. It is extremely challenging (if not impossible) to devise a single identity management solution at the same time able to support a variety of end-users using heterogeneous devices, and suitable for a multitude of environments (e.g., large-scale distributed systems, Internet-of-Things, and Future Internet). As a consequence, the research community has focused on the design of system-specific identity management solutions, in scenarios having a well-defined set of purposes, requirements, and constraints. In this thesis, we approach the issue of fake accounts in large-scale, distributed systems. More specifically, we target systems based on the peer-to-peer paradigm and that can accommodate lightweight, long-term identity management schemes (e.g., file sharing and live streaming networks, collaborative intrusion detection systems, among others); lightweight because users should obtain identities without being required to provide “proof of identity” (e.g., passport) and/or pay taxes; and long-term because users should be able to maintain their identities (e.g., through renewal) for an indefinite period. Our main objective is to propose a framework for adaptively pricing identity requests as an approach to limit Sybil attacks. The key idea is to estimate a trust score for identity requests, calculated as a as function of the number of identities already granted in a given period, and considering their source of origin. Our approach relies on proof of work, and uses cryptographic puzzles as a resource to restrain attackers. In this thesis, we also concentrate on reshaping traditional puzzles, in order to make them “green” and “useful”. The results obtained through simulation and experimentation have shown the feasibility of using green and useful puzzles for identity management. More importantly, they have shown that profiling identity requests based on their source of origin constitutes a promising approach to tackle the dissemination of fake accounts.

Magister Legum - LLM / Black Economic Empowerment (BEE) has been a topic of discussion since the dawn of democracy in April 1994. Due to the entrenched inequalities of the past, economic empowerment is very important for the economic growth of the majority of South Africa’s citizens. However, significant economic enrichment of black people has not been made, despite, economic success, legislation, state policies and programme interventions. This economic growth is to be realised through the use of preferential procurement as a policy tool for BEE. Whilst sufficient legislation has been enacted to regulate preferential procurement, to favour black people, much still seems to be lacking in the enforcement of the laws in public procurement. Central to the challenges of preferential procurement is the disharmony between the Framework legislation governing preferential procurement and BEE. This discord has seen two visions being followed for preferential procurement; the Procurement Act refers to the beneficiaries of BEE as historically disadvantaged individuals (HDI; s) and the goals for BEE are measured through specific goals which promotes narrow empowerment; the BBBEE Act on the other hand defines black people as the recipients of BEE and through the BEE Codes broad-based empowerment is promoted through seven core elements. This congruency has not served the promotion of preferential procurement, it has created a hindrance that frustrates economic growth for those it is intended. The other quandary that undermines the success of preferential procurement is willful practices engaged by both tenderers and public officials; skills deficiency in the adjudication of tenders and self-interest. The success of BEE through preferential procurement is dependent on a coherently legislated procurement environment fortified by perceptive public officials. The objective of this thesis is to analyse the impact of these challenges on the success of preferential procurement. The study will highlight the main practices that defeat the use of preferential procurement. This will include an analysis of the various legislation and the amendments thereto. In addition the enquiry will examine the proficiency of public officials in the adjudication of public tendering. Recommendations for a successful preferential public procurement environment will be made. The proposed thesis will utilise, inter alia, relevant legislation, case law, theses, journals, books and policy documents. / South Africa