This dissertation consists of three essays on modeling and parameter estimation for covariance non-stationary processes. The first essay considers the non-linear deformation of time scale for G(lambda)-stationary processes developed by Jiang, Gray and Woodward [2006]. After the appropriate...

Three major regression-based seasonal unit root tests: the DHF test introduced by Dickey et al (1984), the HEGY test proposed by Hylleberg et al. (1990) and the Kunst test introduced by Kunst (1997) are compared. The regression model for the DHF test is a reduced form of that for the Kunst test....

This dissertation relates to three recent methods of instrument selection in econometrics, namely, the Canonical Correlations Information Criterion (CCIC), the Relevant Moments Selection Criterion (RMSC) and the approximate Mean Square Error Criterion (MSE). Usual canonical correlations measure...

In this thesis, we extend Bai and Perron's (1998, Econometrica, pp. 47-78) method fordetecting multiple breaks to nonlinear models. To that end, we consider an unstable univariatenonlinear least squares (NLS) model with a limited number of parameter shifts occurring atunknown dates. In our...