Skip to main content
. Author manuscript; available in PMC: 2018 Feb 7.
Published in final edited form as: J Causal Inference. 2015 May 14;3(2):237–249. doi: 10.1515/jci-2014-0039

Table 3.

Standardized mean differences for measuring covariate balance.

Data generation scenario
1 2 3 4 5

Description Standard Random sample Selection depends on x and t Weight scales differ Non-linear treatment

Selection s ~ x sx s ~ (x, t) s ~ xt s ~ x
Treatment t ~ x t ~ x t ~ x t ~ x t ~ x2
Fit PS model
Sampling weights PS model PATE
1 None t ~ 1 1.18 1.06 1.10 1.17 0.13
2 None t ~ x 0.10 0.03 0.03 0.09 2.00
3 Covariate t ~ x + sw 0.06 0.03 2.28 1.39 0.89
4 Weight t ~ x 0.04 0.03 0.03 0.04 0.01
PATT
5 None t ~ 1 1.18 1.06 1.10 1.17 0.13
6 None t ~ x 0.17 0.03 0.08 0.16 0.74
7 Covariate t ~ x + sw 0.12 0.03 1.57 0.44 1.10
8 Weight t ~ x 0.12 0.02 0.06 0.11 0.08

Notes: Covariate balance measured with absolute standardized mean differences. All models fit use sampling weights when computing these differences, but vary on whether or how those sampling weights were used in the propensity score model.