Oh that's a fun project -- if you look at regional interest in the US by city, every single city listed has a school with a strong econ program. Google's order of interest: Ithaca (Cornell), New Haven (Yale), Cambridge (Harvard/MIT), Berkeley (Cal), Champaign (UIUC), Ann Arbor (Michigan), Durham (Duke), Providence (Brown), Madison (Wisconsin), Pittsburgh (Pitt/CMU).