. Author manuscript; available in PMC: 2016 Jan 5.

Published in final edited form as: Multivariate Behav Res. 2015 Sep-Oct;50(5):504–519. doi: 10.1080/00273171.2015.1068157

Table 2.

Simulation Study 1, Standardized Bias from Proration – Uniform Item Means, Varied Inter-Item Correlations

Parameter	Items Per Scale	Sample Size	MCAR Mechanism	MAR Mechanism Due to External Variable	MAR Mechanism Due to Complete Items on the Scale
Mean of X	8	200	−0.0042	−0.2219	0.0997
	8	500	0.0022	−0.3423	0.1611

	16	200	0.0089	−0.2169	−0.0386
	16	500	0.0000	−0.3741	−0.0798

Mean of Y	8	200	0.0030	−0.2234	0.1065
	8	500	0.0000	−0.3497	0.1678

	16	200	0.0031	−0.2307	−0.0511
	16	500	0.0000	−0.3590	−0.0867

Variance of X	8	200	−0.1523	−0.2215	−0.0948
	8	500	−0.2611	−0.3748	−0.1634

	16	200	−0.3736	−0.4956^*	−0.3998
	16	500	−0.6121^*	−0.8162^*	−0.6646^*

Variance of Y	8	200	−0.1680	−0.2468	−0.1058
	8	500	−0.2609	−0.3741	−0.1533

	16	200	−0.3738	−0.4976^*	−0.4041^*
	16	500	−0.5919^*	−0.7892^*	−0.6499^*

Covariance	8	200	−0.2211	−0.3424	−0.2140
	8	500	−0.3333	−0.5402^*	−0.3264

	16	200	−0.2166	−0.3742	−0.2436
	16	500	−0.3544	−0.6000^*	−0.3873

Correlation	8	200	−0.1894	−0.2996	−0.2012
	8	500	−0.2803	−0.4751^*	−0.3064

	16	200	−0.0995	−0.2308	−0.1176
	16	500	−0.1655	−0.3693	−0.1799

Regression Coefficient	8	200	−0.1869	−0.2924	−0.1969
	8	500	−0.2755	−0.4630^*	−0.2986

	16	200	−0.0967	−0.2222	−0.1140
	16	500	−0.1594	−0.3580	−0.1755

Note. The table contains standardized bias values for conditions with a 25% item-level missing data rate. The item means were uniform but the inter-item correlations varied.

Standardized bias values greater than or equal to .40 in absolute value are denoted by an asterisk (*).