Pricing Mortgage-Backed Securities (MBS)

This paper presents a pricing formula for MBSs andproposes a specific model for MBS prices thatdescribes the so-called burnout phenomenon ofprepayments due to refinancing. A numerical exampleof the model is demonstrated by Monte Carlosimulation. An estimation procedure is alsodescribed.     

Commercial Mortgage-Backed Securities: Prepayment and Default

One of the major developments in real estate finance during the 1990s was the emergence of a viable market for commercial mortgage backed securities. The growth in this market has spurred greater interest in empirical and theoretical research on commercial mortgage default and prepayment. We employ a competing risks model to examine the default and prepayment behavior of commercial loans underlying CMBS deals. We find that changes in the yield curve have a direct impact on the probability of mortgage termination. Furthermore, we do not find any statistical relationship between LTV and prepayment or default.     

Default Clustering Risks in Commercial Mortgage-Backed Securities

This paper proposes an intensity-based pricing model with default dependence structure for CMBS bonds. Three features are incorporated into the proposed model. First, default is a Poisson jump process defined by a function of mortgage rating information. Second, property risks are modeled using a high dimensional Brownian motion process that captures both systematic risk and idiosyncratic risk in property value. Third, default dependence structure is built into the extended model. Based on a set of input parameters, we simulate various pricing effects on a hypothetical CMBS using the proposed model structure. The results of the base-line intensity model show that yield spreads on CMBS bonds increase in the recovery rate, but decreases in the hazard rate. Security structured with smaller subordination tranche exposes CMBS bonds to higher default risks. The model predicts that default clustering increases required yield spreads of CMBS bonds. At a 70% recovery rate and a 3% default hazard rate, yield spreads of Junior bonds are expected to increase by 169 basis points when counterparty risks increase by 50%. The results highlight the importance of clustering risks associated with counterparty default when valuing CMBS bonds.     

Valuation of Mortgage-Backed Securities Based upon a Structural Approach

This paper studies the valuation of mortgage-backed securities (MBS) based upon a structural approach of several risks involving the prepayment and/or default behavior of mortgagors. For the Kariya and Kobayashi (1999) model using a time-consuming Monte-Carlosimulation, we provide an alternative semi-analytic valuation methodology closely related to solving the (Volterra type) integral equation with respectto the first hitting time density for a curved/flat boundary; consequently that enables us to calculate the MBS price faster and more precisely. Next, to capture the path-dependent prepayment behavior of the interest ratemovements we give some prepayment models based upon a two-dimensional Markov process of the interest rate and its long-run average rate. Third, we study the simultaneous assessment issue of prepayment and defaultrisks, encountered in practice.Finally we discuss the calculation of the joint probability density ofmultiple first hitting times.     

Market Risk of Mortgage-Backed Securities with Consistent Measures

Due to the complex prepayment behavior, mortgage contracts and their derivatives are generally priced using Monte Carlo simulations. The typical approach used by the industry, which involves simulating interest rates under the risk-neutral measure and applying a physically measured prepayment function, is subject to the problem of internal inconsistency. This is the first paper that directly investigates the potential impact of this issue. Following the general equilibrium setting by Cox, Ingersoll and Ross, we incorporate the market risk price parameter to derive the physical interest rate process from an observed yield curve. This allows us to model mortgage values under the consistent physical measures of interest rates and prepayment functions. By analyzing a default-free Ginnie Mae MBS, we find that the mixed measures lead to slower prepayment rate estimates and overpriced mortgage securities by approximately 5%. Further, there can be substantial biases in the duration and convexity measures depending on market condition and the particular security of interest. The internal inconsistency also leads to biased predictions of both expected and stressed returns for different investment horizons. Depending on the particular security, the bias in expected and stressed returns can be either positive or negative. These biases in risk estimates can introduce misallocation of risk-based capital and/or failure in hedging the market risk of a mortgage-related portfolio.

Limits of Arbitrage: Theory and Evidence from the Mortgage-Backed Securities Market

“Limits of Arbitrage” theories hypothesize that the marginal investor in a particular asset market is a specialized arbitrageur rather than a diversified representative investor. We examine the mortgage‐backed securities (MBS) market in this light. We show that the risk of homeowner prepayment, which is a wash in the aggregate, is priced in the MBS market. The covariance of prepayment risk with aggregate wealth implies the wrong sign to match the observed prices of prepayment risk. The price of risk is better explained by a kernel based on MBS market‐wide specific risk, consistent with the specialized arbitrageur hypothesis.     

Analyses of Mortgage-Backed Securities Based on Unobservable Prepayment Cost Processes

We propose a prepayment model of mortgage based on a structural approach in order to analyze prepayment risk of mortgage-backed securities (MBS). We introduce a continuous process named prepayment cost process. Specifically, each mortgager's prepayment time is defined by the first time when her or his prepayment cost process falls below zero, but prepayment cost processes are supposed to be unobservable in the market. We also introduce a risk unique to each loan pool of mortgages, called a loan pool risk (LPR), and we regard LPR as a systematic risk other than interest rate. Using the model, we discuss the conditional distribution of prepayment times and a risk-neutral valuation of pass-through MBS. It is shown that each mortgager's conditional non-prepayment probability and the posterior distribution of LPR play quite important roles in our study.This research is partially supported by Grant-in-Aid for Young Scientists (B) No. 16710108 from the Ministry of Education, Culture, Sports, Science and Technology.     

Valuing Fixed-Income Options and Mortgage-Backed Securities with Alternative Term Structure Models

To value mortgage-backed securities and options on fixed-income securities, it is necessary to make assumptions regarding the term structure of interest rates. We assume that the multi-factor fixed parameter term structure model accurately represents the actual term structure of interest rates, and that the values of mortgage-backed securities and discount bond options derived from such a term structure model are correct. Differences in the prices of interest rate derivative securities based on single-factor term structure models are therefore due to pricing bias resulting from the term structure model. The price biases that result from the use of single-factor models are compared and attributed to differences in the underlying models and implications for the selection of alternative term structure models are considered.     

The Pricing of When-Issued Securities

The observed pricing of when-issued securities would seem to violate the law of one price in financial economics. Generally, when-issued shares sell at a premium over the original shares during the short time when both are traded. This paper examines whether this observed premium could be due to a nonsynchronous trading problem, to the intensity of trading, to the exchange on which the shares are traded, to whether the shares are traded pre-or-post -negotiable commissions, or to the nature of the demand for when-issued relative to the price setting of the specialist. Results indicate that most orders for when-issued securities are buys, that these orders typically take place at the specialist's ask price, and that accounting for this trading mechanism explains the positive premium on when-issued securities.     

Valuation of Residential Mortgage-Backed Securities with Default Risk Using an Intensity-Based Approach

This paper develops a valuation model for fixed-rate mortgages, mortgage pools, and residential mortgage-backed securities (RMBS's) using an intensity-based approach. This model incorporates full prepayment, partial prepayment, and default in valuing a mortgage. Full prepayment is further classified into “refinancing” and “sale of a house” depending on the reason. The time of occurrence of each of these three types of prepayment and default is modeled as the first jump time of a Cox process. Under these conditions, the valuation formula for a mortgage as well as a partial differential equation (PDE) that the mortgage value satisfies is provided. As for implementation of the model, the short-term riskless interest rate and the house price are adopted as state variables. Each intensity process is specified in a manner that allows a jump in intensity depending on the state variables and the borrower's incentive for prepayment or default. Through such specifications, it is shown that our model has characteristics similar to some structural models in previous literature. As for the numerical method for valuation, we propose a simple backward induction technique on a tree instead of the commonly used Monte Carlo method. Additionally, the method for estimating the model is discussed, and the results of numerical simulations are reported.This paper represents the view of the author and does note necessarily the views of the Mitsubishi UFJ Securities Co., Ltd. or members of its staff.     

中国证券业十件大事

1.证监会换帅2.全球股市A股跌幅第二3.创业板退市机制酝酿升级4.中国概念股海外遭猎杀5.新股年内破发频现6.汇金再度出手救市7.有望迎来新红利时代8.打击内幕交易显成效9.RQFII业务资格终获批10.基金跑输大盘     

谈商业银行与证券公司的合作

在当前金融业竞争日趋激烈的形势下，商业银行与证券公司的合作是管理层，商业银行和证券公司三方的共同需要。银证双方应在国家政策允许的范围内，积极探讨并试行银证合作的方法与途径，实现优势互补。     

商业银行贷款定价理论与实践

本文系统阐述了贷款定价的基本理论,对西方商业银行贷款定价主要模式进行了比较分析,结合我国金融市场发展现状和商业银行内部管理体制,提出建立我国商业银行贷款定价体系的建议.     

Commercial Banks in the Securities Business: A Review

This paper analyses the potential effects of commercial banks' expansion into the securities business in the context of the contemporary theory of financial intermediation. The analysis focuses on the gains claimed to emerge with that expansion, particularly the gains due to information advantages and economies of scope, and on the costs also claimed to arise with it; namely, those due to conflicts of interest and safety and soundness considerations. The paper ends with a discussion on how these effects depend on the location of the securities unit within the banking conglomerate.     

Prospectus Earnings Forecasts and the Pricing of New Issues on the Unlisted Securities Market

This paper extends the primarily US based literature on management earnings forecasts to an investigation of the role of prospectus earnings forecasts (Pefs) on the pricing of new issues on the Unlisted Securities Market (USM) in the UK. The analysis finds that Pefs are no more biased but are significantly more accurate than time-series forecasts. In addition, traded prices of USM stocks immediately after flotation are found to be positively related to the information content (unexpected component) of the Pefs. There is, however, no evidence of a relationship between the information content of Pefs and the initial offer price of the USM stocks.     

我国商业银行存款保险定价研究

存款保险制度被公认为现代金融安全网的有机组成部分,但其本身存在着道德风险、逆向选择和委托代理问题。因此如何利用完善的制度设计,尤其是存款保险费率的选择模式以及具体测算就成为关键因素。自1993年提出"建立存款保险基金"构想以来,我国对建立存款保险的研究力度逐年深入。但国内现有对存款保险费率的研究文献存在照搬国外已有模型、分析指标应用不恰当,研究结论差异过大等诸多问题,不仅未能达到确定我国存款保险费率适当水平的目的,反而造成了认识上的混乱。本文在应用Morton期权定价基本模型的基础上,结合理论对该模型的评价缺陷和现实监管评级要求,选取样本指标对测算费率进行修正,这是一种创新性研究方法。通过回归技术和统计手段对样本银行在经营过程中资本状况、盈利能力和管理水平的变动趋势进行了分析,从而使存款保险机构能够实现对投保银行的动态监管和适时处理。     

商业银行次级债定价研究

本文利用Black-Scholes的期权定价思想,把次级债券看成以银行资产为标的的期权组合,研究了次级债的定价问题.模型研究适用于两种不同优先级清偿规则的次级债定价方法、信用利差的性质,并给出实例.     

商业银行融资融券业务探讨

开展融资融券业务是我国商业银行在寻求经营转型过程中实施的一项重要创新措施.本文结合融资融券的现实和发展情况,提出商业银行开拓此项业务的新思路.     

商业银行资本工具创新及定价研究

资本工具的创新可以拓展银行资本补充渠道和空间,提升银行补充资本的能力,强化银行业的资本约束,增强风险管理水平,推动商业银行业务转型,增强服务实体经济的能力.本文在阐述我国资本工具的应用及创新背景的基础上,通过建立二叉树模型,探讨了我国新型资本工具定价问题并提出相关建议.     

期货投资组合交易保证金设置研究——基于Copula模型和极值理论的分析

本文以棉花、铜、天然橡胶三个期货合约为研究对象,基于t-Copula模型,利用Monte Carlo模拟法计算在一定权重下由三个品种构成的期货投资组合的VaR和ES值作为投资组合的保证金数值。Kupiec回溯测试结果表明,t-Copula模型结合极值理论计算出的期货投资组合保证金相比其他方法能够在较好覆盖极端风险的同时降低投资成本。