Do siblings make us happy?

This paper examines the sibling effect on individuals’ happiness. To identify the effect, we explore random gender assignment of siblings, conditional on the number of siblings, among urban residents born before the One Child Policy (1979) in China. We find that having more brothers significantly increases individuals’ happiness. Specifically, having one more brother rather than one sister increases one’s self-reported happiness by 0.038 on a 1- to 5-point scale. The brothers effect is particularly significant among low-income and unstable-income individuals. These results are consistent with findings in early literature, suggesting that brothers provide each other with financial support in case of need.