This paper investigates the implications of time-varying betas in factor models for stock returns. It is shown that a single-factor model (SFMT) with autoregressive betas and homoscedastic errors (SFMT-AR) is capable of reproducing the most important stylized facts of stock returns. An empirical...

The estimation of inflation volatility is important to Central Banks as it guides their policy initiatives for achieving and maintaining price stability. This paper employs three models from the Generalized Autoregressive Conditional Heteroscedasticity (GARCH) family with a view to providing a...

This paper focus on the problems faced in the empirical investigation of the relation between the level and volatility of inflation. Monthly inflation series seem to be affected by both the presence of outliers and conditional heteroscedasticity. First, the paper illustrates the implications...

The recent paper by Ling and Tong (2005) considered a quasi-likelihood ratio test for the threshold in moving average models with errors. This article generalizes their results to the case with GARCH errors, and a new quasi-likelihood ratio test is derived. The generalization is not direct since...

In this paper we introduce a new class of covariance stationary long-memory models on the positive half-line. The overall structure of the models is related to that of GARCH processes of Engle (1982) and Bollerslev (1986), whereby sequence of random variables of interest have multiplicative...

Darbe siekiama aprašyti periodinį ilgos atminties finansinių laiko eilučių elgesį. Remiantis anksčiau sukurtais modeliais, siūlomas h-faktorių Gegenbauer-LARCH modelis, kuris į LARCH tipo proceso sąlyginės dispersijos lygtį įtraukia apibendrintą ilgos atminties filtrą, paremtą...

We use a discrete time analysis, giving necessary and sufficient conditions for the almost sure convergence of ARCH(1) and GARCH(1,1) discrete time models, to suggest an extension of the (G)ARCH concept to continuous time processes. Our COGARCH (continuous time GARCH) model, based on a single...

We use a discrete time analysis, giver necessary and sufficient conditions for the almost sure convergence of ARCH(1) and GARCH(1,1) discrete time models, to suggest an extension of the (G)ARCH concept to continuous time processes. The models, based on a single background driving Lévy process,...

This paper discusses nonparametric kernel regression with the regressor being a d-dimensional ß-null recurrent process in presence of conditional heteroscedasticity. We show that the mean function estimator is consistent with convergence rate p n(T)hd, where n(T) is the number of regenerations...

The hypothesis that stock index returns form a martingale difference sequence (MDS) is tested for 10 European emerging stock markets: the Czech Republic, Estonia, Hungary, Malta, Poland, Russia, the Slovak Republic, Slovenia, Turkey and the Ukraine, using joint variance ratio tests based on...