. Author manuscript; available in PMC: 2010 Jan 4.

Published in final edited form as: J R Stat Soc Ser A Stat Soc. 2008 Jan 1;171(1):179–202. doi: 10.1111/j.1467-985X.2007.00511.x

Table 3.

Variance ratios for ${\hat{β}}_{w}$ in the simplified within group confounding model based on four estimation approaches: subsample data based on simple random subsamples (SRS-sub), combined data based on simple random subsamples (SRS-comb), combined data based on college random subsamples (CRS-comb), combined data based on college random subsamples with ecological racial proportions (CRERS-comb).

Data	k_i = 5	k_i = 10	k_i = 50
SRS - Subsample	1	1	1
SRS - Combined	.817	.925	.987
CRS - Combined	.345	.406	.396
CRERS - Combined	.369	.394	.407