http://www.nomblog.com/35598 So if you want to live longer, get married. (Does not apply to homosexuals) This study shows the health benefits of male-female relationships. Homosexual relationships have much higher mortality rates.
And people with pets live longer. http://www.doctoroz.com/blog/mao-shing-ni-lac-dom-phd/live-longer-pets So, get married and get a dog and you'll live forever!
"Married people have lower mortality rates" Simply because it takes a long time to nag someone to death. // Yes dear, I'll take out the trash as soon as I'm done typing my response on ET.
Causation because it took into account people that were divorced and widowed. Why would you say survivorship bias? Since this is a mortality study, I would assume they only investigate the deaths & not the people still living. You obviously cant judge someones mortality if they are still alive. You cant deny the HR ratios. 1 HR(base stat) for the married couples and 1.37 to 1.89 for everyone else? That is a pretty significant difference.