I have been re-reading Carl Honore's excellent book "In Praise of Slow". Now that the slow movement has been around for a while we should be able to assess how successful it has been. However these are small towns, the Slow City is limited to 50,000 inhabitants, and as such they do not have very sophisticated economic development departments. However the economy page of the first Slow City, Bra's website indicates a clear understanding of the relationship between the Slow philosophy and the economy. It mentions the increasing importance of craftsmanship and tourism.
I am on the case on your behalf to try and find out how the early Slow Cities are faring and have also asked the UK version for a copy of their economic goals. It will be interesting to see how far they differ from other cities.
Incidentally this is part of a larger piece of research I am doing about economic goals, so if anyone out there has a good set from their home town I would be most interested.
If you would like to follow the slow route a bit further you can go to the UK's Citta Slow web site