@techreport{NBERw14002,
 title = "Identification of Treatment Effects Using Control Functions in Models with Continuous, Endogenous Treatment and Heterogeneous Effects",
 author = "Jean-Pierre Florens and James J. Heckman and Costas Meghir and Edward J. Vytlacil",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Working Paper Series",
 number = "14002",
 year = "2008",
 month = "May",
 URL = "http://www.nber.org/papers/w14002",
 abstract = {We use the control function approach to identify the average treatment effect and the effect of treatment on the treated in models with a continuous endogenous regressor whose impact is heterogeneous. We assume a stochastic polynomial restriction on the form of the heterogeneity but, unlike alternative nonparametric control function approaches, our approach does not require large support assumptions.},
}