Saadat¹ wrote that there has only been one study on the association between human offspring sex ratio (proportion male) at birth and parental exposure to electromagnetic fields (EMF). He substantiated this claim with a reference to Irgens et al.² However, I³ cited six other such studies.^4–9 These studies, although not unanimous, cumulatively suggest that both exposed men and exposed women tend to produce significant excesses of daughters. This suggestion is not much changed by the comparatively small samples adduced by Saadat.¹ The point may be illustrated by considerations of standard power analysis.¹⁰ Suppose that you wished to …