Business and Finance world…

Builders brace for brickbats from the Square Mile

July 7th, 2008 piotr zukowski

The extent of the collapse in the housebuilding market will be revealed this week with trading statements from Barratt Developments and Persimmon, two of the sector’s big three.



10 names in frame to value the Rock

July 7th, 2008 piotr zukowski

Around 10 firms have applied to take on the poisoned chalice of valuing Northern Rock, in spite of the threat of possible legal action, Treasury officials have confirmed.



Are There Structural Breaks in Realized Volatility?

July 7th, 2008 piotr zukowski

Constructed from high-frequency data, realized volatility (RV) provides an accurate estimate of the unobserved volatility of financial markets. This paper uses a Bayesian approach to investigate the evidence for structural breaks in reduced form time-series models of RV. We focus on the popular heterogeneous autoregressive (HAR) models of the logarithm of realized volatility. Using Monte Carlo simulations we demonstrate that our estimation approach is effective in identifying and dating structural breaks. Applied to daily S, and P 500 data from 1993-2004, we find strong evidence of a structural break in early 1997. The main effect of the break is a reduction in the variance of log-volatility. The evidence of a break is robust to different models including a GARCH specification for the conditional variance of log(RV).

A Simple Test for GARCH Against a Stochastic Volatility Model

July 7th, 2008 piotr zukowski

GARCH models and Stochastic Volatility (SV) models can both be used to describe unobserved volatility in asset returns. We consider the issue of testing a GARCH model against an SV model. For that purpose, we propose a new and parsimonious GARCH-t model with an additional restricted moving average term, which can capture SV model properties. We discuss model representation, parameter estimation, and our simple test for model selection. Furthermore, we derive the theoretical moments and the autocorrelation function of our new model. We illustrate our model and test for nine daily stock-return series.

Periodic Dynamic Conditional Correlations between Stock Markets in Europe and the US

July 7th, 2008 piotr zukowski

This study extends the dynamic conditional correlation model of Engle (2002, Journal of Business and Economic Statistics 20, 339–350) to allow periodic (day-specific) conditional correlations of shocks across international stock markets. The properties of the resulting periodic dynamic conditional correlation (PDCC) model are examined, focusing particularly on stationarity and the implications for unconditional shock correlations. When applied to the intraweek interactions between six developed European stock markets and the United States over 1993–2005, we find very strong evidence of periodic conditional correlations for the shocks. The highest correlations are generally observed on Thursdays, with these sometimes being twice those on Monday or Tuesday. In addition to these PDCC effects, strong day-of-the-week effects are found in mean returns for the French, Italian, and Spanish stock markets, while periodic effects are also present in volatility for all stock markets except Italy.

VAR Modeling for Dynamic Loadings Driving Volatility Strings

July 7th, 2008 piotr zukowski

The implied volatility of an option as a function of strike price and time to maturity forms a volatility surface. Traders price according to the dynamics of this high dimensional surface. Recent developments that employ semiparametric models approximate the implied volatility surface (IVS) in a finite dimensional function space, allowing for a low dimensional factor representation of these dynamics. This paper presents an investigation into the stochastic properties of the factor loading time series using the vector autoregressive (VAR) framework and analyzes the dynamic relationship of these factors with economic indicators.

Using Exponentially Weighted Quantile Regression to Estimate Value at Risk and Expected Shortfall

July 7th, 2008 piotr zukowski

We propose exponentially weighted quantile regression (EWQR) for estimating time-varying quantiles. The EWQR cost function can be used as the basis for estimating the time-varying expected shortfall associated with the EWQR quantile forecast. We express EWQR in a kernel estimation framework, and then modify it by adapting a previously proposed double kernel estimator in order to provide greater accuracy for tail quantiles that are changing relatively quickly over time. We introduce double kernel quantile regression, which extends the double kernel idea to the modeling of quantiles in terms of regressors. In our empirical study of 10 stock returns series, the versions of the new methods that do not accommodate the leverage effect were able to outperform GARCH-based methods and CAViaR models.

US: 1.95 FedFunds 2008-07-02 NYFed daily fed funds effective rate

July 7th, 2008 piotr zukowski

daily federal funds effective rate for 2008-07-02 is 1.95

It’s American Brandstand: Marketers Underwrite Performers

July 7th, 2008 piotr zukowski

Procter & Gamble, the consumer goods giant, is part of a wave of companies getting into the music business to promote their own products.

Media Talk: Tracking the Olympics Audience Across the NBC Media Universe

July 7th, 2008 piotr zukowski

To provide advertisers a portrait of its Olympics viewership, NBC will be relying on TAMI, an amalgam of existing yardsticks.