Table 1.

Results of simulation study under MAR: comparison of ${\hat{θ}}_{0}$ , ${\hat{θ}}_{I W}$ , ${\hat{θ}}_{D R}$ and ${\hat{θ}}_{D R - N}$ using modified weights, when Z₁ and Z₂ are identical. ε is Gaussian (i.e., ε ~ N(0, 1)) or non-Gaussian (i.e., ε = 20{η – E(η)} with η ~ Beta(5, 1)). True θ is 0.722 for Gaussian ε and 0.675 for non-Gaussian ε. The details of true models and misspecified working models are provided in Section 3.1.

	Gaussian ε					non-Gaussian ε
	RB (%)	SE	SD	SMSE	CR (%)	RB (%)	SE	SD	SMSE	CR (%)
${\hat{θ}}_{G S}$	−0.2	0.036	0.037	0.037	94.0	0.0	0.038	0.038	0.038	95.8
${\hat{θ}}_{0}$	11.6	0.050	0.054	0.099	70.0	10.8	0.057	0.056	0.092	80.4
	Both mean models correctly specified
${\hat{θ}}_{I M P}$	−0.1	0.040	0.042	0.042	95.0	−0.8	0.054	0.054	0.054	94.8
${\hat{θ}}_{I W}$	0.5	0.048	0.052	0.052	93.0	1.0	0.056	0.058	0.059	95.0
${\hat{θ}}_{D R}$	0.0	0.045	0.043	0.043	96.4	0.5	0.057	0.055	0.055	96.4
${\hat{θ}}_{D R - N}$	0.0	0.042	0.043	0.043	94.4	0.5	0.056	0.056	0.056	96.0
	Mean model for $(M 1)$ misspecified
${\hat{θ}}_{I W}$	8.4	0.050	0.054	0.081	78.6	8.0	0.056	0.058	0.079	84.8
${\hat{θ}}_{D R}$	0.0	0.040	0.043	0.043	94.0	0.6	0.052	0.055	0.055	94.4
${\hat{θ}}_{D R - N}$	0.0	0.041	0.043	0.043	95.4	0.4	0.056	0.055	0.055	95.8
	Mean model for $(M 2)$ misspecified
${\hat{θ}}_{D R}$	0.5	0.054	0.050	0.050	96.2	0.9	0.061	0.058	0.058	96.2
${\hat{θ}}_{D R - N}$	0.5	0.050	0.050	0.050	94.0	0.9	0.059	0.058	0.058	95.6
	Both mean models misspecified
${\hat{θ}}_{D R}$	8.4	0.050	0.053	0.081	78.6	7.9	0.057	0.058	0.079	86.0
${\hat{θ}}_{D R - N}$	8.4	0.051	0.053	0.081	79.0	7.9	0.058	0.058	0.079	86.2