Partnership Status, Health, and Mortality: Selection or Protection?

Married individuals have better health and lower mortality than nonmarried people. Studies show that when cohabitants are distinguished from other nonmarried groups, health differences between partnered and nonpartnered individuals become even more pronounced. Some researchers have argued that partnered individuals have better health and lower mortality because a partnership offers protective effects (protection); others have posited that partnered people have better health and lower mortality because healthy persons are more likely to form a union and less likely to dissolve it (selection). This study contributes to this debate by investigating health and mortality by partnership status in England and Wales and analyzing the causes of mortality differences. We use combined data from the British Household Panel Survey and the UK Household Longitudinal Study and apply a simultaneous-equations hazard model to control for observed and unobserved selection into partnerships. We develop a novel approach to identify frailty based on self-rated health. Our analysis shows that partnered individuals have significantly lower mortality than nonpartnered people. We observe some selection into and out of unions on unobserved health characteristics, but the mortality differences by partnership status persist. The study offers strong support for the marital protection hypothesis and extends it to nonmarital partnerships.