Fig. 2From: Correction to: Applied comparison of large-scale propensity score matching and cardinality matching for causal inference in observational researchMatching covariate standardized mean differences after large-scale propensity score matching (PSM) and cardinality matching (CM). Fine balance: exact marginal distributional balance. Violin plots illustrate kernel probability density; the width of the shaded area represents the proportion of observations with the corresponding y-axis valueBack to article page