Different levels of effect sharing among tissues means that effect estimates in some tissues gain more precision than others from the joint analysis. To quantify this, we computed an “effective sample size” (ESS) for each tissue that reflects typical precision of its effect estimates (Supplementary Fig. 6, Supplementary Note). The ESS values are smallest for tissues that show more “tissue-specific” behaviour (e.g., testis, whole blood), and are largest for coronary artery, reflecting its stronger correlation with other tissues.
