Hi there,
I also got accepted to both and I decided to go for the MA Econ Columbia for two reasons. First, I love New York and I know I feel more at home there than in Chicago. And second, even though UChicago is extremely renown for its economics department, I have heard that the MAPSS is more like a collecting pond and not as strong as assumed coming from UChicago. That's just my two cents.
Btw how did you decide eventually since the deadline for Columbia was approaching?
See you maybe in August ;)