-nearest neighbour (KNN) matching estimators of average causal effects. This is an interesting result showing that bootstrap should not … valid inference for KNN matching estimators. We resample "estimated individual causal effects" (EICE), i.e. the difference … respect to the matching covariate, we obtain a bootstrap scheme valid also with heterogeneous causal effects where mild …

selection-on-observables type assumptions using matching or propensity score methods. Much of this literature is highly …