My guess is that Tableau detected the column as Number (Whole) and you need to change the data type to Number (Decimal).
Thank you for your comment, but I did what you mention and the problem was not solved.
Andres - Sorry to hear that didn't work. If you used an extract, make sure to change the data type before taking the extract.
If that still doesn't work, we'll need more information to try to diagnose the problem. Can you attach part of your data file here? Or at least some screen shots.
Thank you for your interest. Fortunately, I was able to solve the issue. First, for those Stata users who like to mine the data first and then export it to Tableau, I used the command “export delimited” instead of the well known “outsheet” command. Also, I exported first a small sample of my data and force tableau to detect it in the way I need it (I did that using the Stata command “outsheet” and it didn’t work). Finally, I exported the full data again and load it over in Tableau. Now, it is working just fine.
Thank you all for your help!