This class defines the R-learner of Xie and Wager (2021) for estimation of the conditional average treatment effect.
Format
An R6 class with public methods to initialize the learner, create a regression task, and access the base learner.
Details
For continuous treatment, this implementation follows the partially linear
effect-model view in which the outcome regression is decomposed using an
A * tau(X) term rather than a fully general treatment-response surface.
When the chosen modifier set V is a strict subset of the adjustment set
W, the natural target is E[Y(1) - Y(0) | V] = E[tau(W) | V]. The current
implementation does not generally target that object in the reduced-modifier
setting. Instead, it learns the overlap-weighted projection
f_R(V) = E[Var(A|W) tau(W) | V] / E[Var(A|W) | V], which simplifies to
E[e(W)(1-e(W)) tau(W) | V] / E[e(W)(1-e(W)) | V] for binary treatment.
Super classes
sl3::Lrnr_base -> hte3::Lrnr_hte -> Lrnr_cate_R
Methods
Inherited methods
sl3::Lrnr_base$assert_trained()sl3::Lrnr_base$base_chain()sl3::Lrnr_base$base_predict()sl3::Lrnr_base$base_train()sl3::Lrnr_base$chain()sl3::Lrnr_base$custom_chain()sl3::Lrnr_base$get_outcome_range()sl3::Lrnr_base$get_outcome_type()sl3::Lrnr_base$predict()sl3::Lrnr_base$predict_fold()sl3::Lrnr_base$print()sl3::Lrnr_base$process_formula()sl3::Lrnr_base$reparameterize()sl3::Lrnr_base$retrain()sl3::Lrnr_base$sample()sl3::Lrnr_base$set_train()sl3::Lrnr_base$subset_covariates()sl3::Lrnr_base$train()sl3::Lrnr_base$train_sublearners()hte3::Lrnr_hte$check_treatment_type()hte3::Lrnr_hte$get_modifiers()hte3::Lrnr_hte$make_metalearner_task()
Method new()
Usage
Lrnr_cate_R$new(base_learner, ...)Arguments
base_learnerA
sl3learner object inheriting fromLrnr_basethat specifies the base supervised learning algorithm used by the meta-learner.