Re: [Gretl-users] unbalanced panel data problem

At first this seemed a simple problem to me, but I have failed to find a solution. I have a very large unbalanced panel data set that I am having difficulty declaring as such. The data set includes a numerical year variable and a numerical month variable (1-12). Then, there are a large number of observations whose numbers vary per month. Gretl had no problem reading the data set, but it was read as undated. At first I thought I simply needed a time index that included both the year and month information in a single variable. So, I created this: series tindex = year + month/100. This created the expected numerical variable. But, when I tried to use this as an index variable in the panel data structure declaration, it doesn't show up in the drop down menu.