Fertility, Marriage and Happiness in Low Fertility Contexts: Evidence from a Study of Danish Twins

Hans-Peter Kohler, University of Pennsylvania

Understanding the determinants of why individuals and couples desire children in below-replacement fertility contexts is of considerable importance for assessing future trends in low and lowest-low fertility countries. In this paper we therefore estimate the contributions of fertility and marriage to subjective wellbeing---or ``happiness''---using a unique data set from Denmark that includes monozygotic (identical) and dizygotic (fraternal) twins. The specific feature of our data then allow us to control for many unobserved endowments (genetic dispositions, family background, socialization, etc.) that affect the fertility/marriage behavior and simultaneously happiness. To our knowledge, the proposed analyses in this paper will yield the first \emph{causal} estimates of the contributions of fertility and marriage to subjective well-being and happiness. In addition, our analyses are likely to reveal important aspects of the valuation of children across gender and across different time points in an individual's life-cycle.