In this study we investigate using the mean reversion processes in financial risk management, as they provide an good description of stock price uctuations and market risks. This paper does not aim at being exhaustive, but gives examples for practically implementable models allowing for stylised...

This paper examines the weak-form efficient market hypothesis (EMH) in the case of the Ghana Stock Exchange (GSE) an emerging market. Daily returns from the Databank Stock Index (DSI) over a 5-year period 1999-2004 were used for the exercise. Random walk (RW) and GARCH(1,1) models are used as...

This study shows that augmented Dickey-Fuller (ADF) test failed to detect covariance nonstationary series. Supportive of Ahamada (2004), this study finds that the cumulative sums of squares procedure in Inclán and Tiao (1994) is useful to complement the ADF test. As illustration, the ADF test...

The present paper puts forward a new hypothesis about the economic circuit, which is a product of Marx’s “period of production” and Keynes’s determination order between investment and savings. It leads to a new definition of profit which excludes any remaining competition between savings...

This paper deals with testing a time series with a structural break in its mean for a unit root when the break date is known. A nonlinear (with respect to coefficients) test equation is used, providing asymptotically efficient estimates. Finite-sample and quasi-asymptotic empirical distributions...

This study examines the sustainability of trade deficit with allowance of structural breaks and seasonal adjustments as both variables have been subject to structural changes and affected by seasons. We find that, in all the cases, there is long run relationship between export and import. This...

This paper studies the asymptotic properties of the quasi-maximum likelihood estimator of ARCH(1) models without strict stationarity constraints, and considers applications to testing problems. The estimator is unrestricted, in the sense that the value of the intercept, which cannot be...

Relevant literature suggests that the most important determinant of health care spending is real GDP. Moreover, there is considerable evidence that health care spending rises at a faster rate than real GDP. This paper uses recently developed tests for the existence of a long run relationship to...

In this paper, we extend Bai and Perron's (1998, Econometrica, pp. 47-78) method for detecting multiple breaks to nonlinear models. To that end, we consider a nonlinear model that can be estimated via nonlinear least squares (NLS) and features a limited number of parameter shifts occurring at...

Lagged variables are often used as instruments when the generalized method of moments (GMM) is applied to time series data. We show that if these variables follow noncausal autoregressive processes, their lags are not valid instruments and the GMM estimator is inconsistent. Moreover, in this...