Before revision:  In particular, we show how to construct the smallest and largest values of the counterfactual as the distribution of unobservables spans nonparametric neighborhoods of the researcher's assumed specification while other `structural' features of the model , e.g. equilibrium conditions, are maintained.
After revision:  In particular, we show how to construct the smallest and largest values of the counterfactual as the distribution of unobservables spans nonparametric neighborhoods of the researcher's parametric specification while other `structural' features of the model , e.g. equilibrium conditions, are maintained.