BTW, I have to roll my eyes at this statement. Columbia already has one of the strongest econ faculty in the world. Arguably stronger than LSE, and LSE has study-abroad arrangements with many colleges (a lot lower than Columbia on the totem pole).
In any case, the faculty at Columbia would be more accomplished (than ND’s) from a purely research standpoint. And Columbia probably does send more undergrads to PhD programs than ND. But fit really should trump all for an undergrad (part of the difference in fit is that Columbia would likely have more kids looking to enter PhD programs).