Hi, I just had to use the solution from section 4.5 of the user guide ("Panel data specifics") which explains how to convert a time-series dataset holding the same conceptual variable for different units (e.g., countries) into a panel dataset with a single variable ("Side-by-side time series", on my A4 version on page 23). So that paragraph is very useful. Two comments or questions on this: 1) I think it's a quite frequent use case. So would it be possible to enable this dataset twist in the GUI under the Data menu somehow? Should I file a feature request? 2) While I was applying the hansl code given in the paragraph, I noticed that as an interim effect of the stack() function the dataset --which was still nominally a time-series thing-- got extended with (N-1)*T time series observations to accommodate the stacked variable. I understand why that is, but obviously at that point the state of the dataset is wrong, so I wonder if this could be somehow avoided. For example by packaging the algorithm for the user such that the interim stage isn't really made public? thanks sven