
Variance-minimising overlap weight for a dual-frame estimator
Source:R/median_frames_dose_native.R
morie_optimal_overlap_weight.RdHartley's estimator is unbiased for every \(\theta\) in [0, 1], so the choice is purely about efficiency. With independent samples the variance \(\theta^2 V_A + (1-\theta)^2 V_B\) is minimised at \(\theta^* = V_B/(V_A + V_B)\) – weight goes to the frame that measures the overlap MORE precisely.
References
Hartley HO (1962). Lohr SL, Rao JNK (2000) JASA 95(449):271-280, doi:10.1080/01621459.2000.10473920 .