The “herbivore men” discourse, which suggests the retreat of young men from dating with regard to their attitudes and behaviors, has not been treated with empirical methods. This study estimates transition probabilities and confidence intervals within the heterosexual relationship status by birth cohort using the restricted ordinary least squares and bootstrap method and examines the “herbivore men” discourse. We used data from The National Fertility Survey report, which indicates the proportions of heterosexual relationship status.

The analysis found that（1）the transition probabilities to a status in which one is not in a relationship（henceforth referred to as “single” ）have been increasing; （2）the transition probabilities to a married status have been decreasing; and（3）the transition probabilities from single to a status in which one has a romantic partner have generally remained flat or changed slightly to an inversed u-shape.