The literature on fertility and happiness has neglected comparative analysis. we investigate the fertility/happiness association using data from the world values Surveys for 86 countries. we fnd that, globally, happiness decreases with the number of children. this association, however, is strongly modifed by individual and contextual factors. most importantly, we find that the association between happiness and fertility evolves from negative to neutral to positive above age 40, and is strongest among those who are likely to beneft most from upward intergenerational transfers. in addition, analyses by welfare regime show that the negative fertility/ happiness association for younger adults is weakest in countries with high public support for families, and the positive association above age 40 is strongest in countries where old-age support depends mostly on the family. overall these results suggest that children are a long-term investment in well-being, and highlight the importance of the life-cycle stage and contextual factors in explaining the happiness/fertility association.