When people tell you their 'perfect' number of kids, they’re usually just making up an excuse for the number of kids they already have.
March 27, 2026
Original Paper
<p>Realized Fertility Outcomes Influence Survey-Reported Fertility Preferences</p>
SSRN · 6359278
The Takeaway
Using the random event of a first-born's sex, researchers found that mothers adjust their reported 'ideal' number of children to match their actual outcomes. This suggests that survey data on family preferences—often used for population policy—doesn't measure actual goals, but rather how people rationalize the 'roll of the dice' from nature.
From the abstract
Survey questions on ideal family size are a widely-used tool in population science, yet their validity remains contentious. We pool data on over five million women from hundreds of Demographic and Health Surveys, to shed new light on the interpretation of these reported ideals. Our research strategy uses the fact that the sex of a woman's first birth is random, and predicts variation in her realized fertility. We ask whether this determinant of fertility outcomes influences later reported fertil