I think choosing your grad school according to the faculty you`d like to work with is a good idea. I am not particularly informed about the old faculty at JHU but in academia it is usually considered to be better to work with young faculty as they are gonna be more productive and ambitious in research and publishing. So based on the info you`ve given, Ohio State seems like a better option for you, which also has a pretty good ranking in Economics as far as I know.