Iteratively re-estimates the synthetic control excluding one contributing donor at a time, holding the predictor weights V fixed at their baseline values (Abadie, Diamond & Hainmueller 2015, footnote 20). The spread of the leave-one-out ATT estimates shows how much the result hinges on any single donor.
Arguments
- fit
A sharp
coresynthobject fromscm_fit()withmethod = "scm".- weight_threshold
Only donors whose baseline weight exceeds this value are dropped (removing a zero-weight donor cannot change the fit). Default
1e-6.
Value
A list with:
att_original: baseline ATTresults: data.frame with one row per excluded donor (donor,weight,att_loo)att_range: range of the leave-one-out ATTs
Details
For penalised fits (lambda_pen used), the same penalty is re-applied in
each leave-one-out QP.
