Partial information about contagion risk, self-exciting processes and portfolio optimization : [Version 18 April 2013]

This paper compares two classes of models that allow for additional channels of correlation between asset returns: regime switching models with jumps and models with contagious jumps. Both classes of models involve a hidden Markov chain that captures good and bad economic states. The distinctive feature of a model with contagious jumps is that large negative returns and unobservable transitions of the economy into a bad state can occur simultaneously. We show that in this framework the filtered loss intensities have dynamics similar to self-exciting processes. Besides, we study the impact of unobservable contagious jumps on optimal portfolio strategies and filtering

Dynamic Credit Investment in Partially Observed Markets

We consider the problem of maximizing expected utility for a power investor who can allocate his wealth in a stock, a defaultable security, and a money market account. The dynamics of these security prices are governed by geometric Brownian motions modulated by a hidden continuous time finite state Markov chain. We reduce the partially observed stochastic control problem to a complete observation risk sensitive control problem via the filtered regime switching probabilities. We separate the latter into pre-default and post-default dynamic optimization subproblems, and obtain two coupled Hamilton-Jacobi-Bellman (HJB) partial differential equations. We prove existence and uniqueness of a globally bounded classical solution to each HJB equation, and give the corresponding verification theorem. We provide a numerical analysis showing that the investor increases his holdings in stock as the filter probability of being in high growth regimes increases, and decreases his credit risk exposure when the filter probability of being in high default risk regimes gets larger

Crisis-Robust Bond Portfolios.

Asset allocation; bond market; volatility; portfolio management;

The History of the Quantitative Methods in Finance Conference Series. 1992-2007

This report charts the history of the Quantitative Methods in Finance (QMF) conference from its beginning in 1993 to the 15th conference in 2007. It lists alphabetically the 1037 speakers who presented at all 15 conferences and the titles of their papers.

A Primer on Financial Contagion

This paper presents a unified framework to highlight possible channels for the international transmission of financial shocks. We first review the different definitions and measures of contagion used in the literature. We then use a simple multi-country asset pricing model to cast the main elements of the current debate on contagion and provide a stylized account of how a crisis in one country can spread to the world economy. In particular, the model shows how crises can be transmitted across countries, without assuming market imperfections or DG KRF portfolio management rules. Finally, tracking our classification, we survey the results obtained in the empirical literature on contagion.contagion, financial crisis, contagion

Using Markov-Switching models in US stocks optimal portfolio selection in a Black–Litterman context (Part 1)

In this study, we tested the benefit of using Markov-Switching (M-S) models to forecast the views of the 26 most traded stocks in the US in a Black–Litterman (B–L) optimal selection context. With weekly historical data of these stocks from 1 January 1980, we estimated and simulated (from 7 January 2000, to 7 February 2022) three portfolios that used M-S views in each stock and blended them with the market equilibrium views in a B–L context. Our position was that the B–L optimal portfolios could generate alpha (extra return) against a buy-and-hold and an actively managed portfolio with sample portfolio parameters (à la Markowitz, SampP). Our results suggest that the outperformance of the B–L managed portfolios holds only in the short term. In the long-term, the performance of the B–L portfolios, the SampP, and the market portfolio are statistically equal in terms of returns or their mean–variance efficiency in an ex-ante or ex-post analysis.Junta de Extremadur

Tests of an International Capital Asset Pricing Model with Stocks and Government Bonds and Regime Switching Prices of Risk and Intercepts

The paper tests a conditional multivariate International Capital Asset Pricing Model for US, Japanese and European stocks and government bonds, covering the period 1993-2001. Time variation in the prices of market and currency risk is modelled by means of synchronous regime switching. The paper also explores the statistical significance and time variation of asset specific intercept terms, again using synchronous regime switching. The prices of risk are found to be highly time varying. The price of market risk is statistically significant, and the international CAPM risk premia are validated, although currency risk premia are not statistically significant. However, the intercept terms are typically large and significant, implying an overall rejection of the international CAPM, and suggesting that additional, unidentified pricing factors contribute to return expectations.CAPM; Multivariate GARCH-in-Mean

The quest for banking stability in the euro area: The role of government interventions

We build upon a Markov-Switching Bayesian Vector Autoregression (MSBVAR) model to study how the credit default swaps market in the euro area becomes an important chain in the propagation of shocks through the entire financial system. The study sheds light on the regime-dependent interconnectedness between the risk of investing in banking and public sector bonds and provides novel evidence that a rise in sovereign debt, due to the countercyclical fiscal policy measures, is perceived by stock market investors as a burden on growth prospects. We also document that government interventions in the banking sector deteriorate the credit risk of sovereign debt. Higher risk premium required by investors for holding riskier government bonds depresses the sovereign debt market, it impairs banks’ balance sheets, and it depresses the collateral value of loans leading to bank retrenchment. The ensuing two-way banking-fiscal feedback loop indicates that government interventions do not necessarily stabilize the banking sector