balance_ml              Multilevel covariate balance diagnostics
estimate_att_ml         Treatment effect estimation with cluster-robust
                        standard errors
ml_match                Within-cluster nearest-neighbour matching with
                        dual-balance optimisation
ml_ps                   Cluster-aware propensity score estimation
ml_weight               Multilevel inverse probability weights
plot_overlap_ml         Plot propensity score overlap between treatment
                        groups
sens_ml                 Tipping-point sensitivity analysis for omitted
                        cluster confounding
simulate_ml_data        Simulate clustered observational data
