Although the setup of our simulation study focused on a simplified scenario, we can draw a few conclusions by comparing the results to that of the data analysis. Based on simulation results, if the causal SNPs are the same and have the same effect sizes in all EA and Hispanic/Latino populations, we would expect that EA-based SNP selection combined with either EA or META weights would have optimal performance. This was the pattern of results for the anthropometric traits, however, not for blood count or blood pressure traits. Therefore, we hypothesize that there may be differences in effect sizes between population groups for those traits. This is in agreement with the work of Coram et al. (2017) who assumed different effect sizes between populations, and found that estimating effect for risk prediction purposes is useful in ethnically-matched population, while SNP selection using EA GWAS is generally appropriate. Moreover, for platelet count, diastolic blood pressure, and pulse pressure, EA selection worked better with HCHS/SOL weights. In simulations, this happened when either the LD of the selected SNP with the causal one
