This paper analyzes the causal relationship between marriage and subjective well-being using a 17-year longitudinal dataset. It finds that happier singles are more likely to get married, and that the benefits of marriage vary significantly between couples. Factors such as division of labor and education level influence well-being, with women and families with young children benefiting more. Large differences in education levels negatively affect life satisfaction. The study also shows that marriage increases life satisfaction, but this effect is more pronounced for those who marry at a younger age. The analysis suggests that selection effects play a significant role, with happier individuals more likely to marry. The study also finds that the benefits of marriage are not uniform across all couples, with those who have larger differences in education levels experiencing lower satisfaction. The paper concludes that marriage can contribute to well-being, but the extent of this benefit depends on various factors such as education, labor division, and family structure. The study highlights the importance of considering these factors in understanding the relationship between marriage and well-being.This paper analyzes the causal relationship between marriage and subjective well-being using a 17-year longitudinal dataset. It finds that happier singles are more likely to get married, and that the benefits of marriage vary significantly between couples. Factors such as division of labor and education level influence well-being, with women and families with young children benefiting more. Large differences in education levels negatively affect life satisfaction. The study also shows that marriage increases life satisfaction, but this effect is more pronounced for those who marry at a younger age. The analysis suggests that selection effects play a significant role, with happier individuals more likely to marry. The study also finds that the benefits of marriage are not uniform across all couples, with those who have larger differences in education levels experiencing lower satisfaction. The paper concludes that marriage can contribute to well-being, but the extent of this benefit depends on various factors such as education, labor division, and family structure. The study highlights the importance of considering these factors in understanding the relationship between marriage and well-being.