Is it identity all the way down? From supersubstantivalism to composition as identity and back again

We argue that, insofar as one accepts either supersubstantivalism or strong composition as identity for the usual reasons, one has (defeasible) reasons to accept the other as well. Thus, all else being equal, one ought to find the package that combines both views—the Identity Package—more attractive than any rival package that includes one, but not the other, of either supersubstantivalism or composition as identity.