9.20 Extended haplotype homozygosity
The haplotype-based class of selection statistics quantifies long haplotypes that result from a selective sweep.
Extended haplotype homozygosity (EHH) is defined as the probability that any two haplotypes in a population are homozygous at SNPs in specific genomic region. EHH should be elevated in regions under historical selection, because a sweep causes one haplotype to rise to high frequency, and decay as you move further from the site under selection.