51 |
Discrete time modeling of subprime mortgage credit / M.C. SenosiSenosi, Mmamontsho Charlotte January 2010 (has links)
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.
|
52 |
Discrete time modeling of subprime mortgage credit / M.C. SenosiSenosi, Mmamontsho Charlotte January 2010 (has links)
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.
|
53 |
Fatores determinantes do preço de imóveisNakazawa, Denis Keith 28 May 2013 (has links)
Submitted by Denis Nakazawa (denisnak@hotmail.com) on 2013-06-12T10:02:00Z
No. of bitstreams: 1
Fatores Determinantes do Preço de Imóveis (Denis)_vf (pos-banca).pdf: 582940 bytes, checksum: a0fa5f51d08621702a0529597eb29f5f (MD5) / Este estudo tem como objetivo determinar os principais fatores macroeconômicos que influenciam a formação do preço de imóveis, tomando como base o mercado imobiliário residencial da cidade de São Paulo entre os anos de 2001 e 2012. Para capturar o efeito endógeno do PIB, da taxa de juros e da bolsa de valores sobre o preço de imóveis, optou-se por um modelo VAR. Concluiu-se que, dentre as variáveis, o PIB foi o fator mais preponderante na formação do preço, chegando a ter um impacto quase três vezes superior à taxa de juros. Não foram encontradas evidências estatísticas significativas do efeito da bolsa sobre o preço dos imóveis. Constatou-se ainda que choques no PIB e na taxa de juros demoram, no mínimo, um ano para começarem a refletir sobre o preço. Essas conclusões foram mais robustas no período anterior à crise imobiliária americana de 2008. / This article aims to identify the main economic determinants of house prices, based on the Sao Paulo residential market between the years 2001 and 2012. A VAR model was used to capture the endogenous dynamic among GNP, interest rate, equity and house prices. Among the variables, GNP was the most preponderant factor, having an impact almost three times superior than interest rate. No significant statistical evidence was found relating equity to housing price. Furthermore, house prices took at least one year to respond to shocks in the GNP and interest rate. These conclusions were more robust in the period previous to the American subprime mortgage crises of 2008.
|
54 |
Testing the Global Banking Glut HypothesisPunzi, Maria Teresa, Kauko, Karlo 03 1900 (has links) (PDF)
This paper presents VAR results on the recent economic history of the U.S and focuses on the dependence of U.S. macrofinancial variables on international capital flows.
Both gross and net flows are included in the analysis. The results indicate that cross-border funding has affected the build-up in the U.S. housing market irrespective of how these flows are defined and measured. Both the savings glut hypothesis and the banking glut hypothesis are supported by these findings. However, net banking flows appear to explain the higher volatility in the increase in house prices as well as the mortgage loan boom. (authors' abstract) / Series: Department of Economics Working Paper Series
|
55 |
Srovnání cen rodinného domu v různých částech města Brna v letech 2015 a 2016 / Comparison of house prices in different parts of the city of Brno in 2015 and 2016Drcmánková, Hana January 2016 (has links)
Diploma thesis deals with price comparison of family house in Brno – Královo Pole between 2015 and 2016. This family house is located near of the town center and then will be as a simulation moved to the outskirts, Brno – Líšeň. House prices are determined by observed price and market value. The task is to find out and evaluate the price differences, dependents to the valuation time and the place. I will make summary of factors that affect these prices.
|
56 |
Essays in empirical labor, housing and social network economicsNgoundjou Nkwinkeum, George Aurore Dupin 10 1900 (has links)
Cette thèse explore les deux sujets suivants: (i) les déterminants de la participation à la population
active des personnes âgées aux États-Unis; (ii) le rôle du réseau social dans le niveau de revenus de
travail des immigrants récents au Canada.
Plus précisément, le chapitre 1 utilise les données du Health and Retirement Study (HRS) pour
fournir des estimations de l’effet causal du prix des maisons au niveau local sur les décisions d’offre
de travail des individus âgés aux États-Unis, au cours de la période du boom immobilier 1994-
2004. Le prix des maisons est instrumentalisé par des variations spatiales et temporelles de chocs
plausiblement exogènes de l’offre de crédit. Les estimations suggèrent que le boom immobilier
durant la période considérée pourrait expliquer jusqu’à deux tiers des sorties de la population active
des hommes âgés aux États-Unis.
Le chapitre 2 répond à la question: les personnes en bonne santé sont-elles plus susceptibles
de rester sur le marché du travail lorsque le chômage augmente? Ce travail fournit des estimations
empiriques de l’impact relatif des chocs de chômage au niveau local sur la participation au marché
du travail des américains âgés ayant des états de santé hétérogènes. Cette étude montre que la
plupart des départs de travailleurs âgés pendant la Grande récession peuvent être attribués à de
mauvaises conditions de santé, telles que mesurées, avant la récession.
Enfin, le chapitre 3 analyse l’effet du fait de vivre dans un quartier où la majorité des résidents
appartient à des minorités visibles sur les gains des résidents permanents qui sont arrivés à Montréal,
Vancouver et Toronto en 2001. Dans l’ensemble, cette recherche documente un effet négatif
du regroupement ethnique sur les gains des immigrants récents au Canada et l’explique par "l’effet
d’aiguillage". / This thesis explores the following two topics : (i) determinants of labor force participation at older
ages in the US ; (ii) the role of social network in the earnings of recent immigrants in Canada.
Specifically, Chapter 1 provides estimates of the causal effect of local house prices on the labor
supply decisions of older workers in the US during the 1994-2004 housing boom period using data
from the Health and Retirement Study (HRS). Local house prices are instrumented by plausible
exogenous spatial and time-varying credit supply shocks. The estimates suggest that the housing
boom accounted for about two thirds of older men labor force exit during the studied period.
Chapter 2 responds to the question : are people in good health more likely to stay in the labor
market when unemployment rises? This work provides empirical estimates of the relative impact
of local unemployment shocks on the labor force participation of US older workers with heterogeneous
health conditions. This study documents that most of the labor force exit of older workers
during the Great recession can be attributed to poor health conditions measured before the recession.
Finally, Chapter 3 analyses the effect of living in a neighborhood where the majority of the
residents belongs to visible minority groups on the earnings of permanent residents who landed
in Montreal, Vancouver and Toronto in 2001. Overall, this research documents a negative effect
of ethnic clustering on the earnings of recent immigrants in Canada and explain it by the "referral
effect".
|
57 |
Predicting House Prices on the Countryside using Boosted Decision Trees / Förutseende av huspriser på landsbygden genom boostade beslutsträdRevend, War January 2020 (has links)
This thesis intends to evaluate the feasibility of supervised learning models for predicting house prices on the countryside of South Sweden. It is essential for mortgage lenders to have accurate housing valuation algorithms and the current model offered by Booli is not accurate enough when evaluating residence prices on the countryside. Different types of boosted decision trees were implemented to address this issue and their performances were compared to traditional machine learning methods. These different types of supervised learning models were implemented in order to find the best model with regards to relevant evaluation metrics such as root-mean-squared error (RMSE) and mean absolute percentage error (MAPE). The implemented models were ridge regression, lasso regression, random forest, AdaBoost, gradient boosting, CatBoost, XGBoost, and LightGBM. All these models were benchmarked against Booli's current housing valuation algorithms which are based on a k-NN model. The results from this thesis indicated that the LightGBM model is the optimal one as it had the best overall performance with respect to the chosen evaluation metrics. When comparing the LightGBM model to the benchmark, the performance was overall better, the LightGBM model had an RMSE score of 0.330 compared to 0.358 for the Booli model, indicating that there is a potential of using boosted decision trees to improve the predictive accuracy of residence prices on the countryside. / Denna uppsats ämnar utvärdera genomförbarheten hos olika övervakade inlärningsmodeller för att förutse huspriser på landsbygden i Södra Sverige. Det är viktigt för bostadslånsgivare att ha noggranna algoritmer när de värderar bostäder, den nuvarande modellen som Booli erbjuder har dålig precision när det gäller värderingar av bostäder på landsbygden. Olika typer av boostade beslutsträd implementerades för att ta itu med denna fråga och deras prestanda jämfördes med traditionella maskininlärningsmetoder. Dessa olika typer av övervakad inlärningsmodeller implementerades för att hitta den bästa modellen med avseende på relevanta prestationsmått som t.ex. root-mean-squared error (RMSE) och mean absolute percentage error (MAPE). De övervakade inlärningsmodellerna var ridge regression, lasso regression, random forest, AdaBoost, gradient boosting, CatBoost, XGBoost, and LightGBM. Samtliga algoritmers prestanda jämförs med Boolis nuvarande bostadsvärderingsalgoritm, som är baserade på en k-NN modell. Resultatet från denna uppsats visar att LightGBM modellen är den optimala modellen för att värdera husen på landsbygden eftersom den hade den bästa totala prestandan med avseende på de utvalda utvärderingsmetoderna. LightGBM modellen jämfördes med Booli modellen där prestandan av LightGBM modellen var i överlag bättre, där LightGBM modellen hade ett RMSE värde på 0.330 jämfört med Booli modellen som hade ett RMSE värde på 0.358. Vilket indikerar att det finns en potential att använda boostade beslutsträd för att förbättra noggrannheten i förutsägelserna av huspriser på landsbygden.
|
58 |
Three essays in household financeChangwony, Frederick Kibon January 2013 (has links)
This thesis explores the impact of two behavioural finance concepts, social psychology and psychology, on household financial decisions. Under social psychology, I investigate whether the variety and intensity of social engagement enhances stock market participation. With regard to psychology, I examine two behavioural biases. First, I investigate whether mental accounting influences portfolio choice in three asset classes and whether financial advice and housing tenure increase (decrease) the effects of mental accounts on portfolio choice. Second, I examine whether households’ self-reported housing wealth are anchored on published house price indices and whether anchoring bias is mediated by market information, mortgage refinancing decisions and social factors. The main contributions and findings in the three studies are as follows. First, although there is an elaborate body of research concerning the relationship between social engagement mechanisms and portfolio choice, most studies investigate specific mechanisms in isolation. Using three waves in the British Household Panel Survey (BHPS), I bring together five social engagement measures in one model and show that socially engaged individuals are more likely to participate in the stock market. Consistent with Granovetter’s (1973) theory of social networks I find that a weak tie (measured by social group involvement) has a positive effect on stock market participation whereas a strong tie (measured by talking to neighbours) has no effect. More trusting individuals are more likely to participate in the stock market, as are those who identify with a political party. In contrast, the degree to which religion is important appears to have little impact. These results are robust using different specifications. Overall, the results of this study demonstrate that the likelihood of stock market participation increases with the variety and intensity of social engagement. Second, despite the established theoretical underpinnings of mental accounting in behavioural portfolio theory (BPT) and recent extensions, not much is known about their implications in real life situations. I use a recent UK household survey, the Wealth and Assets Survey (WAS), which has comprehensive information about financial assets to investigate whether there are differences in the ownership and portfolio share of three asset classes among individuals who exhibit no mental account, a single mental account and multiple mental accounts, and the conditional influences of financial advice, housing, cognitive ability, time preference and risk tolerance. Overall I find that mental accounting together with financial advice and housing tenure explain variations in both the probability of ownership and portfolio share in the three asset classes. Households that exhibit a single mental account have low share of investments in, and are less likely to own, a risky asset when compared to those that exhibit no mental account or exhibit multiple mental accounts. I also find that, when compared to having no mental account, exhibiting a single mental account or multiple mental accounts increases both the probability and investment share in a fairly safe asset but decreases portfolio share in safe assets. In addition, among those that exhibit a single mental or multiple mental accounts, financial advice decreases portfolio share in risky assets and fairly safe assets and increases portfolio share in safe assets. Housing tenure increases both the probability and portfolio share in risky assets, decreases portfolio share in fairly safe assets and increases portfolio share in safe assets. These results are consistent using multi-equation regressions, sub-samples, reparametrised variables and poisson regressions. Finally, as little is known about how households derive the self-reported house prices estimates that are commonly used to determine housing wealth, the third study examines whether households are anchored on published house price indices. The key conjecture is that, while assessing the values of their homes, homeowners place more weight on house price news at the expense of property characteristics and other market information. I find support for this hypothesis using sixteen waves of the BHPS, multiple methods, and both regional and national house price indices. I conclude that changes in self-reported housing wealth are anchored on changes in published house price indices. Specifically, ownership through a mortgage and greater financial expectations increase anchoring effects while mortgage refinancing decreases the effects. Moreover, use of money raised from refinancing for home investment, as opposed to other consumption purposes, has a positive association with change in self-reported house value and both uses reduce anchoring bias. In addition, I find that computer use increases anchoring bias and, among social engagement mechanisms, religiosity reduces anchoring while other measures have no effect. These results are robust to internal instrumental variables, national aggregate house prices, alternative indices and sub-samples.
|
59 |
不動產評價之空間計量與地理統計 / Spatial Econometrics and Geostatistics for Real Estate Valuation陳靜宜, Chen, Jing Yi Unknown Date (has links)
近年來由於地理資訊系統(GIS)的快速發展發,空間資料分析開始受到重視並在社會科學領域中逐漸扮演重要的角色。雖然一般的統計方法已在傳統資料分析上發展已久,然而它們卻不能有效地說明空間性資料,並且無法充分處理空間相依或空間異質性問題。一般而言,空間資料分析主要有兩個分派:模型導向學派與資料導向學派。本文研究目的在於應用空間統計方法合理且充分地評估房地產價值,研究方法包含地理統計(克利金和共克利金)、地理加權迴歸與空間特徵價格模型等,並且以台中市不動產資料進行實證探究。這項新的研究技術在不動產評價領域中將可提供更好的解析能力,使其在評價過程中或是不動產投資決策時,成為一個更強而有力的分析工具。 / In recent years, spatial data analysis has received significant awareness and played an important role in social science because of the rapid development of Geographic Information System (GIS). Although classic statistical methods are attractive in traditional data analysis, they cannot be executed seriously for spatial data. Standard statistical techniques didn’t sufficiently deal with spatial dependence or spatial heterogeneity issues. Generally, the model-driven method and the data-driven method are mainly the two branches of the spatial data analysis. The purpose of this paper is to apply spatial statistics methods including geostatistical methods (kriging and cokiging), geographically weighted regression, and spatial hedonic price models to real estate analysis. It seems to be completely reasonable and sufficient. The real estate data in Taichung city (Taiwan) is used to carry out our exploration. These techniques give better insight in the field of real estate assessment. They can apply a good instrument in mass appraisal and decision concerning real estate investment.
|
60 |
Residential mortgage loan securitization and the subprime crisis / S. ThomasThomas, Soby January 2010 (has links)
Many analysts believe that problems in the U.S. housing market initiated the 2008–2010 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 mortgages,
securitization, as well as data. 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 and
securitization 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 thesis, the primary subprime agents that we consider are house appraisers (HAs), mortgage
brokers (MBs), mortgagors (MRs), servicers (SRs), SOR mortgage insurers (SOMIs), trustees,
underwriters, credit rating agencies (CRAs), credit enhancement providers (CEPs) and monoline
insurers (MLIs). Furthermore, 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). 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 or policymaking role. Most of the aforementioned agents and
banks are assumed to be risk neutral with SOR being the exception since it can be risk (and regret)
averse on occasion. The main aspects of the SMC - subprime mortgages, securitization, as well as
data - 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 subprime SORs' risk and profit as well as their 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 mortgage losses. In addition, we
show how high loan–to–value ratios due to declining housing prices curtailed the refinancing of
subprime mortgages, while low ratios imply favorable house equity for subprime MRs.
Chapter 3 investigates the securitization of subprime mortgages into structured mortgage products
such as subprime residential mortgage–backed securities (RMBSs) and collateralized debt obligations
(CDOs). In this regard, our discussions focus on information, risk and valuation as well as
the role of capital under RMBSs and RMBS CDOs. Our research supports the view that incentives
to monitor mortgages has been all but removed when changing from a traditional mortgage model to a subprime mortgage model. In the latter context, we provide formulas for IB's profit
and valuation under RMBSs and RMBS CDOs. This is illustrated via several examples. Chapter 3
also explores the relationship between mortgage securitization and capital under Basel regulation
and the SMC. This involves studying bank credit and capital under the Basel II paradigm where
risk–weights vary. Further issues dealt with are the quantity and pricing of RMBSs, RMBS CDOs
as well as capital under Basel regulation. Furthermore, we investigate subprime RMBSs and their
rates with slack and holding constraints. Also, we examine the effect of SMC–induced credit rating
shocks in future periods on subprime RMBSs and RMBS payout rates. A key problem is whether
Basel capital regulation exacerbated the SMC. Very importantly, the thesis answers this question
in the affirmative.
Chapter 4 explores issues related to subprime data. In particular, we present mortgage and securitization
level data and forge connections with the results presented in Chapters 2 and 3.
The work presented in this thesis is based on 2 peer–reviewed chapters in books (see [99] and [104]),
2 peer–reviewed international journal articles (see [48] and [101]), and 2 peer–reviewed conference
proceeding papers (see [102] and [103]). / Thesis (Ph.D. (Applied Mathematics))--North-West University, Potchefstroom Campus, 2011.
|
Page generated in 0.102 seconds