Gender of children and birth timing.

We address the impact of the gender of children on birth timing. Our findings suggest that a preference to balance the gender of children affects the timing of births, not a preference for either sons or daughters. At parity 2, women with children of the same sex time a third birth more rapidly than women with a boy and a girl. At parity 1, women with a boy time second births more rapidly than women with a girl. This seemingly anomalous finding is explained, however, by the fact that women with boys are more likely than women with girls to be married at any point in time and thus less likely to have disrupted fertility careers.