Thanks a lot for the reply. Finance (asset pricing) is one of the two fields I want to do. The other is macro. I'm afraid that finance PhD students do not have good access to professors in the Econ department? I don't know if this is true at Columbia.But I know there are cases that Econ students have B-School professors as their advisers.
Again, I greatly appreciate any suggestions or information. I really hope I can make the decision soon so that the one I decline can go to someone else on the waiting list.