Dutch research funding, gender bias, and Simpson’s paradox

Based on, among other criteria, three consecutive years of grant applications to the “Veni programme” of the Netherlands Organization for Scientific Research (NWO), van der Lee and Ellemers (1) conclude that these data “provide compelling evidence of gender bias in personal grant applications to obtain research funding.” One of the main results this claim is based upon is that of the 1,635 applications by males, 17.7% were successful, whereas of the 1,188 applications by females, only 14.4% were successful. When applying the χ2 test to the data, the authors found a P value of 0.045 (1). This conclusion is based on the application of an inappropriate statistical procedure, and is therefore questionable, due to the so-called “Simpson’s paradox.