Anke C. Zimmermann and Richard A. Easterlin. "Happily ever after? Cohabitation, marriage, divorce, and happiness in Germany".
In Germany the life satisfaction of those in first marriages traces the following average course. Starting from a baseline of life satisfaction in noncohabiting years one or more years prior to marriage, those who cohabit prior to marriage have an increase in life satisfaction significantly above the baseline. In the year of marriage and that immediately following, the life satisfaction of those in first marriages, prior cohabitors and noncohabitors combined, increases to a value even further above the baseline, significantly higher than for premarital cohabitors. Thereafter, life satisfaction of those in first marriages drops, but remains significantly above the baseline, at the same level as for premarital cohabitors. Compared with the population generally, those in first marriages are selective with regard to a number of socioeconomic characteristics, but not in regard to personality traits. Those whose first marriage ends in separation or divorce have a life satisfaction trajectory in the years before and during marriage not significantly different from that described above, but separation or divorce reduces this group’s life satisfaction to the original baseline value. This group differs significantly from the first marriage population as a whole in its selectivity - lower socioeconomic status and personality traits less conducive to marriage. The roots of prospective dissolution thus apparently lie in this group’s distinctive socioeconomic and personality traits, and not in a disparate course of life satisfaction in the first years of marriage.