Search results for " volatility."
showing 10 items of 107 documents
Role of noise in a market model with stochastic volatility
2006
We study a generalization of the Heston model, which consists of two coupled stochastic differential equations, one for the stock price and the other one for the volatility. We consider a cubic nonlinearity in the first equation and a correlation between the two Wiener processes, which model the two white noise sources. This model can be useful to describe the market dynamics characterized by different regimes corresponding to normal and extreme days. We analyze the effect of the noise on the statistical properties of the escape time with reference to the noise enhanced stability (NES) phenomenon, that is the noise induced enhancement of the lifetime of a metastable state. We observe NES ef…
Public sector wage premium and output volatility in the European Union
2018
This study seeks to uncover the role played by the public sector wage premium in explaining the output volatility. Furthermore, the study also explores the factors that might substantiate the cross-country differences in the volatility of the public sector wage premium. Using cross-sectional regression analysis for the European Union countries, the findings indicate that more volatile public sector wage premium is associated with higher fluctuations in the private sector employment and less stable growth. Findings also suggest that volatility of the public sector wage premium tends to be larger in countries with smaller governments and in countries where collective bargaining is the predomi…
Mean Escape Time in a System with Stochastic Volatility
2007
We study the mean escape time in a market model with stochastic volatility. The process followed by the volatility is the Cox Ingersoll and Ross process which is widely used to model stock price fluctuations. The market model can be considered as a generalization of the Heston model, where the geometric Brownian motion is replaced by a random walk in the presence of a cubic nonlinearity. We investigate the statistical properties of the escape time of the returns, from a given interval, as a function of the three parameters of the model. We find that the noise can have a stabilizing effect on the system, as long as the global noise is not too high with respect to the effective potential barr…
Volatility Effects on the Escape Time in Financial Market Models
2008
We shortly review the statistical properties of the escape times, or hitting times, for stock price returns by using different models which describe the stock market evolution. We compare the probability function (PF) of these escape times with that obtained from real market data. Afterwards we analyze in detail the effect both of noise and different initial conditions on the escape time in a market model with stochastic volatility and a cubic nonlinearity. For this model we compare the PF of the stock price returns, the PF of the volatility and the return correlation with the same statistical characteristics obtained from real market data.
SEA presidential address: Group connectivity and cooperation
2011
A model-free methodology is used for the first time to estimate a daily volatility index (VIBEX-NEW) for the Spanish financial market.We use a public data set of daily option prices to compute this index and showthat daily changes in VIBEXNEW display a negative, tight contemporaneous relationship with IBEX daily returns, contrary to other common volatility indicators, as an implied volatility indicator or a GARCH(1,1) conditional volatility model. This relationship is approximately symmetric to the sign on VIBEX-NEW changes and asymmetric to the IBEX-35 returns sign, which make it clearly a suitable volatility index for the Spanish stock market. We also examine the relationship between curr…
The determinants of public deficit volatility
2009
This paper empirically analyzes the political, institutional and economic sources of public deficit volatility. Using the system-GMM estimator for linear dynamic panel data models and a sample of 125 countries analyzed from 1980 to 2006, we show that higher public deficit volatility is typically associated with higher levels of political instability and less democracy. In addition, public deficit volatility tends to be magnified for small countries, in the outcome of hyper-inflation episodes and for countries with a high degree of openness.
Volatility Transmission Models: A Survey
2005
This study reviews the literature on volatility transmission in order to determine what we have learnt about the different methodologies applied. In particular, GARCH, regime switching and stochastic volatility models are analysed. In addition, this study covers several concrete aspects such as their scope of application, the overlapping problem, the concept of efficiency and asymmetry modelling. Finally, emerging topics and unanswered questions are identified, serving as an agenda for future research.
Growth Volatility and the Structure of the Economy
2011
The aim of the chapter is twofold: (i) to propose a methodology to compute the growth rate volatility of an economy and (ii) to investigate the relationship between growth volatility and economic development through the lenses of the structural characteristics of an economy. We study a large cross-section of countries in the period 1970–2009, controlling for the stability of the estimates in two subperiods: 1970:1989 (Period I) and 1990:2009 (Period II). Our main findings are (i) the degree of trade openness has a destabilizing effect, while the degree of financial openness has not a significant effect; (ii) the size of the public sector displays a U-shaped relationship with growth volatili…
Volatility co-movements: a time scale decomposition analysis
2013
In this paper we investigate short-run co-movements before and after the Lehman Brothers’ collapse among the volatility series of US and a number of European countries. The series under investigation (implied and realized volatility) exhibit long-memory and, in order to avoid missspecification errors related to the parameterization of a long memory multivariate model, we rely on wavelet analysis. More specifically, we retrieve the time series of wavelet coefficients for each volatility series for high frequency scales, using the Maximal Overlapping Discrete Wavelet transform and we apply Maximum Likelihood for a factor decomposition of the short-run covariance matrix. The empirical evidence…
Volatility co-movements: a time scale decomposition analysis
2014
In this paper we are interested in detecting contagion from US to European stock market volatilities in the period immediately after the Lehman Brothers’ collapse. The analysis, based on a factor decomposition of the covariance matrix of implied and realized volatilities, is carried for different sub-samples (identified as normal and crisis periods) and across different (high) frequency bands. In particular, the analysis is split in two stages. In the first stage, we retrieve the time series of wavelet coefficients for each volatility series for high frequency scales, using the Maximal Overlapping Discrete Wavelet transform and, in a second stage, we apply Maximum Likelihood for a factor de…