It is well-known that interest rates are extremely persistent, yet they are best modeled and understood as stationary processes. These properties are contradictory in the workhorse Gaussian affine term structure model in which persistent data often result in unit roots that imply...

We revisit the debate on the sustainability of the current account dynamics in the US. Using the concept of sustainability as the ability to meet the long run intertemporal budget constraint, we test for unit roots in the US current account for the 1960-2004 period. We argue that there are...

This paper argues that typical applications of panel unit root tests should take possible nonstationarity in the volatility process of the innovations of the panel time series into account. Nonstationarity volatility arises for instance when there are structural breaks in the innovation...