We propose a discrete-time multivariate model where lagged levels of the process enter both the conditional mean and the conditional variance. This way we allow for the empirically observed persistence in time series such as interest rates, often implying unit-roots, while at the same time...

The long-run and short-run structure of the Danish manufacturing export sector is analyzed within a cointegrated vector autoregressive model. The price variables of the analysis can be characterized as integrated of second order, I(2), but long-run homogeneity seems to cancel the I(2)-trend...

The effects of innovational outliers and additive outliers in cointegrated vector autoregressions are examined and it is analyzed how outliers can be modelled with dummy variables. Using a Monte Carlo simulation it is illustrated how misspecified dummies may distort inference on the...

We characterize the restrictions imposed by the minimal I(2)-to-I(1) transformation that underlies much applied work, e.g. on money demand relationships or open-economy pricing relationships. The relationship between the parameters of the original I(2) vector autoregression, including the...