Economists are primarily interested in the effects of childbirth on the labour supply and the earnings of the mothers, and extensive studies have been conducted in these areas.1 More recently, two strands of literature on childbirth and the labour-market outcomes of women draw particular interests: one focuses on the effect of maternity/parental-leave policies on the post-childbirth employment of [...] The birth of a child has an immediate negative effect on the employment of the mother because upon the birth of a child, the benefits of staying at home and the costs of working rise for the mother. [...] For the narrow sample of Canadian mothers, our results indicate that (a) the earnings drop for the mothers during the year of childbirth varied around 40%, and the maternity/parental leave benefits compensated for about half of this drop; (b) the negative effects of childbirth on the earnings of the mothers declined over the post-childbirth years and the result from the most flexible model (fixed [...] The second observation from Figure 1 is that the short-term post-childbirth employment rates of successive cohorts of Canadian mothers increased from the mid-1980s to the end of the 1990s and then started to decline in the early 2000s. [...] Earnings of Canadian mothers before and after childbirth A simple measure of the effect of childbirth on the earnings of mothers is to compare the pre- and post-childbirth earnings of the mothers.