Memoria para obtener el título de Periodista / Desde su aparición en la tierra, los seres humanos han entendido la necesidad de asociarse para cubrir desde sus necesidades más básicas hasta las más suntuarias. Los sociólogos destacan como una característica inherente a su naturaleza el ser gregarios. Junto con la asociatividad vino el desarrollo de la economía y después sus teorías al respecto. En la segunda mitad del siglo XIII, los neoclásicos Adam Smith y David Ricardo cimentaron las bases del libre mercado, al determinar que entre las aspiraciones de oferentes y demandantes existía un punto de equilibrio que permitía determinar el precio de los productos y servicios. Smith incluso entrega un modelo de un hombre que calzaría perfecto en un sistema de libre mercado: el Homo Economicus , una persona que muestra un comportamiento racional en materia económica, cuyas preferencias de productos y servicios obedecen a decisiones pensadas en base a sus necesidades reales y que procura maximizar las utilidades. Esta visión ideal asume que, en el uso de su capacidad de raciocinio, el individuo toma decisiones informadas. Y lo que resulta más curioso es que el “egoísmo natural” de los humanos es un motor importante del intercambio comercial. Esta es la base moral en la que descansa el libre mercado.

This dissertation consists of three essays on monetary economics. The first two essays have a focus on the zero lower bound on the nominal interest rate (ZLB) and the Great Recession. In the first essay, I investigate optimal discretionary monetary policy under the ZLB in the case of a distorted steady state due to monopoly and taxation. I find that the central bank in a more distorted economy would cut the interest rate less aggressively under a particular adverse demand shock. This occurs because the ZLB is less likely to bind and the economy escapes from the ZLB sooner. In addition, I show that the conventional linear-quadratic method is not accurate when the ZLB binds. In the second essay, I model the role of subprime lending, deleveraging and an incomplete financial market in driving an economy to the liquidity trap with binding ZLB. There are two key features that differentiate my work from the current literature of deleveraging and the ZLB. First, I endogenize the debt limit of borrowing-constrained households by tying it to the market value of collateral assets. Second and more importantly, I allow for subprime lending. I am able to show that the second feature drives the economy to the ZLB more likely under an adverse shock to the credit market. When the ZLB binds, a great recession emerges with a free fall in output and the price level, mostly due to the Fisherian debt deflation that puts more debt burden on the borrowers. The third essay examines the role of habit formation in solving the persistence problem - output response is transient and not hump-shaped under a monetary shock - in the conventional state dependent pricing model. Intuitively, incorporating habit formation makes consumers less aggressive in spending under a shock, resulting in more persistent response of output. With a moderate habit formation, I am able to show that the model produces hump-shaped and very persistent response of output under a monetary growth shock.

Despite being governed by several laws aimed at preventing racial inequality in access to housing and credit resources, the mortgage lending market remains a contributor to racial and place-based disparities in homeownership rates, wealth, and access to high-quality community resources. Scholarship has identified persistent disparities in mortgage loan approval rates and subprime lending between white borrowers and those from other racial and ethnic groups, and between white neighborhoods and neighborhoods with high levels of non-white residents. Against this backdrop, the mortgage lending industry is undergoing rapid, technology-driven changes in risk assessment and application processing. Traditional borrower risk-assessment methods including face-to-face discussions between lenders and applicants and the prominent use of FICO credit scores have been replaced or supplemented by automated decision-making tools at a new generation of institutions known as fintech lenders. Little is known about the relationship between lenders using these new tools and the racial and spatial disparities that have long defined the wider mortgage market. Given the well-documented history of discrimination in lending along with findings of technology-driven racial inequality in other economic sectors, fintech lending’s potential for racial discrimination warrants increased scrutiny. This dissertation compares the lending outcomes of traditional and fintech mortgage lenders in the United States depending on applicant and neighborhood racial characteristics. Using data from the Home Mortgage Disclosure Act, an original dataset classifying lenders as fintech or traditional, and an array of complimentary administrative data sources, it provides an assessment of the salience of race and place in the rates at which mortgage loans from each lender type are approved and assigned subprime terms. Results from a series of regression-based quantitative analyses suggest fintech mortgage lenders, like traditional mortgage lenders, approve and deny loans and distribute subprime credit at disparate rates to white borrowers and neighborhoods relative to nonwhite borrowers and neighborhoods. Findings suggest that policymakers and regulators must increase their oversight of fintech lenders, ensuring that further advances in lending technology do not concretize longstanding racial and spatial disparities.

The subprime mortgage crisis and the resultant inflationary monetary policy in the USA have left the Chinese economy subject to four risks in particular. First, China's exports to the USA might continue to decline. Second, in the medium term, the higher US inflation rate will lead to a weak dollar, which will negatively affect China's exports. Third, in the long term, when the US Federal Reserve decreases money supply to control inflation, the US economy might enter another recession, hurting China's exports further. Fourth, China's foreign exchange reserve assets might suffer heavy losses when the US inflation rate rises. Conventional foreign exchange investment strategies are insufficient for dealing with these four risks. Investment by China in the major US banks is suggested in the present paper. This strategy would mitigate if not eliminate all four risks. China could gain considerable financial returns on investments with only moderate risk.

Trend and panel data analyses are used to determine the role of financial variables in GDP growth differences during the last global recession. Real variables are implemented in order to absorb real shocks and give a better (less biased) estimation of the effects of those nominal (financial) shocks. Results indicate an important role of Stock Market correlations.

No description available.

This dissertation examines the overlap of the racial composition of a neighborhood and the existence of a dual mortgage market in which prime and subprime lenders serve different neighborhoods and borrowers. Does subprime lending represent the democratization of credit or does it serve to track people by race? This dissertation employs Home Mortgage Disclosure Act Data, U.S. Census Data and the HUD Subprime Lender List to identify subprime loans. I use Hierarchical Linear Modeling to predict the likelihood of subprime for a borrower in Philadelphia, Baltimore, San Francisco and Alameda County California. The findings demonstrate that blacks and borrowers in black neighborhoods have a higher likelihood of originating a subprime loan than whites or borrowers in white neighborhoods. Further, blacks borrowing in largely white neighborhoods have an even higher likelihood of originating a subprime loan compared to their white neighbors than do blacks borrowing in largely black neighborhoods. These findings indicate that subprime lenders not only serve different neighborhoods, but also different borrowers regardless of the neighborhood in which they are borrowing and support the existence of a dual mortgage market that is defined by race. The results from the analysis examining the consequences of subprime lending for neighborhoods indicate that after controlling for neighborhood characteristics, the positive relationship between earlier and later rates of subprime lending disappears. Also, while higher rates of subprime refinance lending were associated with a decrease in neighborhood median income in 2000, subprime lending was associated with positive changes in median house value and percent of homeowners that are black in the neighborhood, although the effects of subprime on median house value disappeared after controlling for neighborhood conditions. The study points to the continued difficulties that black borrowers and borrowers in black neighborhoods face in obtaining a fair loan. As lending practices are reformed, it is important to keep in mind the need to ensure that minority borrowers who are in the position to afford a home loan maintain the ability to get a loan, but increased care must be taken to ensure that they obtain the ability to do so on fair terms. / Sociology

Le premier volet de cette thèse traite de l’évaluation du risque de crédit. Après un chapitre introductif offrant une synthèse technique des modèles de risque, nous nous intéressons à la modélisation de la dépendance entre les risques de défaut par les copules qui permettent de mieux fonder les mesures du risque de crédit. Ces dernières assurent une description intégrale de la structure de dépendance et ont l’avantage d’exprimer la distribution jointe en termes des distributions marginales. Nous les appréhendons en termes probabilistes telles qu’elles sont désormais familières, mais également selon des perspectives algébriques, démarche à certains égards plus englobante que l’approche probabiliste. Ensuite, nous proposons un modèle général de pricing des dérivés de crédit inspiré des travaux de Cherubini et Luciano (2003) et de Luciano (2003). Nous évaluons un Credit Default Swap « vulnérable », comprenant un risque de contrepartie. Nous y intégrons la Credit Valuation Adjustment (CVA)préconisée par Bâle III pour optimiser l’allocation du capital économique. Nous reprenons la représentation générale de pricing établie par Sorensen et Bollier (1994) et contrairement aux travaux cités ci-dessus, le paiement de protection ne survient pas forcément à l’échéance du contrat. La dépendance entre le risque de contrepartie et celui de l’entité de référence est approchée par les copules. Nous examinons la vulnérabilité du CDS pour des cas de dépendance extrêmes grâce à un choix de copule mixte combinant des copules usuelles « extrêmes ». En variant le rho de Spearman, la copule mixte balaie un large spectre de dépendances, tout en assurant des closed form prices. Le modèle qui en résulte est adapté aux pratiques du marché et facile à calibrer.Nous en fournissons une application numérique. Nous mettons ensuite en évidence le rôle des dérivés de crédit en tant qu’instruments de couvertures mais aussi comme facteurs de risque, accusés d’être à l’origine de la crise des subprime. Enfin, nous analysons cette dernière ainsi que celle des dettes souveraines, héritant également de l’effondrement du marché immobilier américain. Nous proposons à la suite une étude de soutenabilité de la dette publique des pays périphériques surendettés de la zone euro à l’horizon 2016. / The first part of this thesis deals with the valuation of credit risk. After an introductory chapter providing a technical synthesis of risk models, we model the dependence between default risks with the copula that helps enhancing credit risk measures. This technical tool provides a full description of the dependence structure; one could exploit the possibility of writing any joint distribution function as a copula, taking as arguments the marginal distributions. We approach copulas in probabilistic terms as they are familiar nowadays, then with an algebraic approach which is more inclusive than the probabilistic one. Afterwards, we present a general credit derivative pricing model based on Cherubini and Luciano (2003) and Luciano (2003). We price a “vulnerable”Credit Default Swap, taking into account a counterparty risk. We consider theCredit Valuation Adjustment (CVA) advocated by Basel III to optimize theeconomic capital allocation. We recover the general representation of aproduct with counterparty risk which goes back to Sorensen and Bollier (1994)and differently from the papers mentioned above, the payment of protectiondoes not occur necessarily at the end of the contract. We approach the dependence between counterparty risk and the reference credit’s one with the copula. We study the sensitivity of the CDS in extreme dependence cases with a mixture copula defined in terms of the “extreme” ones. By varying the Spearman’s rho, one can explore the whole range of positive and negative association. Furthermore, the mixture copula provides closed form prices. Our model is then closer to the market practice and easy to implement. Later on, we provide an application on credit market data. Then, we highlight the role of credit derivatives as hedging instruments and as risk factors as well since they are accused to be responsible for the subprime crisis. Finally, we analyze the subprime crisis and the sovereign debt crisis which arose from the U.S. mortgage market collapse as well. We then study the public debt sustainability of the heavily indebted peripheral countries of the eurozone by 2016.

Many analysts believe that problems in the United States housing market initiated the 2007-2009 global financial crisis. In this regard, the subprime mortgage crisis (SMC) shook the foundations of the financial industry by causing the failure of many iconic Wall Street investment banks and prominent depository institutions. This crisis stymied credit extension to households and businesses thus creating credit crunches and, ultimately, a global recession. This thesis specifically discusses the SMC and its components, causes, consequences and cures in relation to subprime mortgage origination, data as well as bank bailouts. In particular, the SMC has highlighted the fact that risk, credit ratings, profit and valuation as well as capital regulation are important banking considerations. With regard to risk, the thesis discusses credit (including counterparty), market (including interest rate, basis, prepayment, liquidity and price), tranching (including maturity mismatch and synthetic), operational (including house appraisal, valuation and compensation) and systemic (including maturity transformation) risks. The thesis introduces the IDIOM hypothesis that postulates that the SMC was largely caused by the intricacy and design of subprime agents, mortgage origination that led to information problems (loss, asymmetry and contagion), valuation opaqueness and ineffective risk mitigation. It also contains appropriate examples, discussions, timelines as well as appendices about the main results on the aforementioned topics. Numerous references point to the material not covered in the thesis, and indicate some avenues for further research. In the sequel, the banks that we study are subprime interbank lenders (SILs), subprime originators (SORs), subprime dealer banks (SDBs) and their special purpose vehicles (SPVs) such as Wall Street investment banks and their special structures as well as subprime investing banks (SIBs). Furthermore, the primary subprime agents that we consider are house appraisers (HAs), mortgage brokers (MBs), mortgagors (MRs), servicers (SRs), trustees, underwriters and credit enhancement providers (CEPs). Also, the insurers involved in the subprime market are originator mortgage insurers (OMIs) and monoline insurers (MLIs). The main components of the SMC are MRs, the housing market, SDBs/hedge funds/money market funds/SIBs, the economy as well as the government (G) and central banks. Here, G either plays a regulatory, bailout or policymaking role. Most of the aforementioned banks and agents are assumed to be risk neutral with SOR being the exception since it can be risk (and regret) averse on occasion. The three main aspects of the SMC - subprime mortgage origination, data and bailouts - that we cover in this thesis and the chapters in which they are found are outlined below. In Chapter 2, we discuss the dynamics of SORs' capital, information, ratings, risk and valuation under mortgage origination. In particular, we model subprime mortgages that are able to fully amortize, voluntarily prepay or default and construct a discrete-time model for SOR risk and profit incorporating costs of funds and mortgage insurance as well as loan losses. Furthermore, a constrained optimal valuation problem for SORs under mortgage origination is solved. In addition, we show how high loan-to-value ratios curtailed the refinancing of subprime mortgages, while low ratios imply favorable house equity for subprime MRs. Chapter 2 also explores the relationship between Basel capital regulation and the SMC. This involves studying bank credit and capital under Basel regulation. Further issues dealt with are the quantity and pricing of subprime mortgages as well as credit ratings under Basel capital regulation. A key problem is whether Basel capital regulation exacerbated the SMC. Very importantly, the thesis answers this question in the affirmative. Chapter 3 contains subprime data not presented in Chapters 2. We present other mortgage data that also have connections with the main subprime issues raised. In Chapter 4, a troubled SOR's recapitalization by G via subprime bank bailouts is discussed. Our research supports the view that if SOR is about to fail, it will have an incentive not to extend low risk mortgages but rather high risk mortgages thus shifting risk onto its creditors. Here, for instance, we analyze the efficiency of purchasing toxic structured mortgage products from troubled SORs as opposed to buying preferred and common equity. In this regard, we compare the cases where SORs' on-balance sheet mortgages are fully amortizing, voluntarily prepaying (refinancing and equity extraction) and involuntarily prepaying (defaulting). If bailing out SORs considered to be too big to fail involves buying assets at above fair market values, then these SORs are encouraged ex-ante to invest in high risk mortgages and toxic structured mortgage products. Contrary to the policy employed by G, purchasing common (preferred) equity is always the most (least) ex-anteand ex-post-efficient type of capital injection. Our research confirms that this is true irrespective of whether SOR volunteers for recapitalization or not. In order to understand the key results in Chapters 2 to 4, a working knowledge of discrete-time stochastic modeling and optimization is required. The work presented in this thesis is based on a book (see [103]), 2 peer-reviewed international journal articles (see [51] and [105]), 2 peer-reviewed chapters in books (see [104] and [110]) and 4 peer-reviewed conference proceedings paper (see [23], [106], [107] and [109]). / Thesis (Ph.D. (Applied Mathematics))--North-West University, Potchefstroom Campus, 2011.

Many analysts believe that problems in the United States housing market initiated the 2007-2009 global financial crisis. In this regard, the subprime mortgage crisis (SMC) shook the foundations of the financial industry by causing the failure of many iconic Wall Street investment banks and prominent depository institutions. This crisis stymied credit extension to households and businesses thus creating credit crunches and, ultimately, a global recession. This thesis specifically discusses the SMC and its components, causes, consequences and cures in relation to subprime mortgage origination, data as well as bank bailouts. In particular, the SMC has highlighted the fact that risk, credit ratings, profit and valuation as well as capital regulation are important banking considerations. With regard to risk, the thesis discusses credit (including counterparty), market (including interest rate, basis, prepayment, liquidity and price), tranching (including maturity mismatch and synthetic), operational (including house appraisal, valuation and compensation) and systemic (including maturity transformation) risks. The thesis introduces the IDIOM hypothesis that postulates that the SMC was largely caused by the intricacy and design of subprime agents, mortgage origination that led to information problems (loss, asymmetry and contagion), valuation opaqueness and ineffective risk mitigation. It also contains appropriate examples, discussions, timelines as well as appendices about the main results on the aforementioned topics. Numerous references point to the material not covered in the thesis, and indicate some avenues for further research. In the sequel, the banks that we study are subprime interbank lenders (SILs), subprime originators (SORs), subprime dealer banks (SDBs) and their special purpose vehicles (SPVs) such as Wall Street investment banks and their special structures as well as subprime investing banks (SIBs). Furthermore, the primary subprime agents that we consider are house appraisers (HAs), mortgage brokers (MBs), mortgagors (MRs), servicers (SRs), trustees, underwriters and credit enhancement providers (CEPs). Also, the insurers involved in the subprime market are originator mortgage insurers (OMIs) and monoline insurers (MLIs). The main components of the SMC are MRs, the housing market, SDBs/hedge funds/money market funds/SIBs, the economy as well as the government (G) and central banks. Here, G either plays a regulatory, bailout or policymaking role. Most of the aforementioned banks and agents are assumed to be risk neutral with SOR being the exception since it can be risk (and regret) averse on occasion. The three main aspects of the SMC - subprime mortgage origination, data and bailouts - that we cover in this thesis and the chapters in which they are found are outlined below. In Chapter 2, we discuss the dynamics of SORs' capital, information, ratings, risk and valuation under mortgage origination. In particular, we model subprime mortgages that are able to fully amortize, voluntarily prepay or default and construct a discrete-time model for SOR risk and profit incorporating costs of funds and mortgage insurance as well as loan losses. Furthermore, a constrained optimal valuation problem for SORs under mortgage origination is solved. In addition, we show how high loan-to-value ratios curtailed the refinancing of subprime mortgages, while low ratios imply favorable house equity for subprime MRs. Chapter 2 also explores the relationship between Basel capital regulation and the SMC. This involves studying bank credit and capital under Basel regulation. Further issues dealt with are the quantity and pricing of subprime mortgages as well as credit ratings under Basel capital regulation. A key problem is whether Basel capital regulation exacerbated the SMC. Very importantly, the thesis answers this question in the affirmative. Chapter 3 contains subprime data not presented in Chapters 2. We present other mortgage data that also have connections with the main subprime issues raised. In Chapter 4, a troubled SOR's recapitalization by G via subprime bank bailouts is discussed. Our research supports the view that if SOR is about to fail, it will have an incentive not to extend low risk mortgages but rather high risk mortgages thus shifting risk onto its creditors. Here, for instance, we analyze the efficiency of purchasing toxic structured mortgage products from troubled SORs as opposed to buying preferred and common equity. In this regard, we compare the cases where SORs' on-balance sheet mortgages are fully amortizing, voluntarily prepaying (refinancing and equity extraction) and involuntarily prepaying (defaulting). If bailing out SORs considered to be too big to fail involves buying assets at above fair market values, then these SORs are encouraged ex-ante to invest in high risk mortgages and toxic structured mortgage products. Contrary to the policy employed by G, purchasing common (preferred) equity is always the most (least) ex-anteand ex-post-efficient type of capital injection. Our research confirms that this is true irrespective of whether SOR volunteers for recapitalization or not. In order to understand the key results in Chapters 2 to 4, a working knowledge of discrete-time stochastic modeling and optimization is required. The work presented in this thesis is based on a book (see [103]), 2 peer-reviewed international journal articles (see [51] and [105]), 2 peer-reviewed chapters in books (see [104] and [110]) and 4 peer-reviewed conference proceedings paper (see [23], [106], [107] and [109]). / Thesis (Ph.D. (Applied Mathematics))--North-West University, Potchefstroom Campus, 2011.