  We investigate a model of one-to-one matching with transferable utility and
general unobserved heterogeneity. Under a separability assumption that
generalizes Choo and Siow (2006), we first show that the equilibrium matching
maximizes a social gain function that trades off exploiting complementarities
in observable characteristics and matching on unobserved characteristics. We
use this result to derive simple closed-form formulae that identify the joint
matching surplus and the equilibrium utilities of all participants, given any
known distribution of unobserved heterogeneity. We provide efficient algorithms
to compute the stable matching and to estimate parametric versions of the
model. Finally, we revisit Choo and Siow's empirical application to illustrate
the potential of our more general approach.
