TABLE 2.

Median and IQR (in parentheses) of relative efficiency when the true correlation model is NEX. Parameter specifications: number of clusters $I=24$, WP‐ICC ${\alpha }_0$ is 0.05, and the CAC is 0.5

Working	$J$	CV	No within‐cluster	Within‐cluster	Within‐cluster	Within‐cluster
correlation			imbalance	imbalance pattern 1	imbalance pattern 2	imbalance pattern 4
NEX	3	0.25	0.988 (0.985, 0.991)	0.986 (0.974, 0.996)	0.964 (0.953, 0.975)	0.963 (0.951, 0.975)
		0.75	0.901 (0.880, 0.919)	0.888 (0.833, 0.930)	0.864 (0.816, 0.905)	0.862 (0.815, 0.905)
		1.25	0.762 (0.724, 0.796)	0.726 (0.648, 0.796)	0.716 (0.640, 0.786)	0.703 (0.622, 0.779)
	5	0.25	0.988 (0.986, 0.991)	0.986 (0.977, 0.995)	0.958 (0.949, 0.966)	0.959 (0.949, 0.967)
		0.75	0.903 (0.882, 0.920)	0.888 (0.849, 0.923)	0.865 (0.824, 0.898)	0.864 (0.820, 0.905)
		1.25	0.765 (0.730, 0.798)	0.725 (0.659, 0.785)	0.705 (0.639, 0.765)	0.708 (0.647, 0.773)
	13	0.25	0.989 (0.986, 0.991)	0.985 (0.981, 0.988)	0.975 (0.971, 0.978)	0.977 (0.972, 0.980)
		0.75	0.905 (0.886, 0.922)	0.878 (0.851, 0.902)	0.868 (0.841, 0.889)	0.872 (0.847, 0.895)
		1.25	0.770 (0.735, 0.802)	0.703 (0.661, 0.744)	0.697 (0.653, 0.741)	0.696 (0.655, 0.741)
IND	3	0.25	0.955 (0.945, 0.964)	0.958 (0.942, 0.972)	0.878 (0.863, 0.892)	0.880 (0.865, 0.896)
		0.75	0.721 (0.673, 0.763)	0.767 (0.696, 0.831)	0.693 (0.629, 0.756)	0.700 (0.643, 0.756)
		1.25	0.501 (0.440, 0.560)	0.591 (0.508, 0.659)	0.532 (0.464, 0.611)	0.523 (0.453, 0.604)
	5	0.25	0.954 (0.937, 0.972)	0.971 (0.944, 0.994)	0.899 (0.878, 0.919)	0.903 (0.881, 0.928)
		0.75	0.722 (0.656, 0.776)	0.818 (0.751, 0.887)	0.760 (0.696, 0.816)	0.760 (0.689, 0.824)
		1.25	0.502 (0.430, 0.564)	0.639 (0.554, 0.725)	0.593 (0.513, 0.671)	0.593 (0.505, 0.681)
	13	0.25	0.953 (0.927, 0.978)	0.987 (0.973, 1.000)	0.975 (0.961, 0.988)	0.973 (0.957, 0.989)
		0.75	0.714 (0.641, 0.783)	0.909 (0.866, 0.945)	0.891 (0.847, 0.928)	0.891 (0.851, 0.928)
		1.25	0.492 (0.416, 0.573)	0.778 (0.714, 0.839)	0.770 (0.694, 0.832)	0.770 (0.700, 0.825)