This paper contains a Lagrange multiplier test of the hypothesis that the covariance matrix of a multivariate time series model is constant over time. It is further assumed that under the alternative, the error variances are time-varying whereas the correlation remain constant over time. Under...

This paper applies the maximum likelihood panel cointegration method of Larsson and Lyhagen (2007) to test the strong PPP hypothesis using data for the G7 countries. This method is robust in several important dimensions relative to previous methods, including the well-known issue of...

This paper applies the maximum likelihood panel co-integration method of Larsson and Lyhagen (2007) to test the strong PPP hypothesis using data for the G7 countries. This method is robust in several important dimensions relative to previous methods, including the well-known issue of...