This article comments on the conclusion reached by Akre et al. in their study on human fertility. Akre et al. concluded that subfertility (measured as a waiting time to pregnancy of 1 year) decreased from 1983 to 1993 in Sweden and that the decline followed a birth cohort pattern. In addition, they speculated that the decrease in subfertility during the 1980s is mainly due to the eradication of gonorrhea. However, the data they presented does not seem to justify their conclusion. The researchers did not study the consequences of truncation of the waiting-time distribution in 1993 and 1983, the association between smoking and infertility, and declining semen quality in order to further support their conclusion.
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