It is possible that your economics department will request that you submit your title for approval long before the dissertation itself is due. This is to stop candidates attempting unsuitable topics, but it does mean that you’ll commit to a title long before the final piece is written.
If this applies to you, then it is probably best to keep your title as general as possible. In particular, most people submit their title before they’ve tracked down the data they need for any empirical work. It is best to avoid pledging to study patenting in Latin America from 1970-85 if you don’t have the dataset already, as you might not track it down.