We study the dimensional reduction of 3d QFTs with N=2 supersymmetry. In particular, we are interested in deriving dualities between 2d N=(2,2) theories starting from 3d dualities. Our main tool is the supersymmetric index, ie, the partition function on S^2 x S^1, which formally reduces to the partition function on S^2 as the radius of the circle goes to zero. There are various technical subtleties in this limit of the index which reflect physical subtleties in the reduction of the theories. We reproduce several known 2d N=(2,2) dualities and find evidence for some new ones.