I've done plenty of research.  You aren't including the issue of divorce.  Married men who are happily married are, indeed, the happiest.  Married men who get divorced, on the other hand, are among the most miserable, and the most likely to commit suicide.  As men, we see what happens when a man gets divorced.  Better to be stable and single than divorced, economically devastated and suicidal.  Considering the stats on the chances of divorce, there's a reason that there's a growing movement for men to abandon marriage in all but extraordinary circumstances because of this risk.