I 've done a lot of reading on this the past couple of days. An article in a journal on Marriage says that the divorce rate peaked in 1980 at 40% and that it has declined since then.  There are a number of factors that complicate figuring out the actual rate, economics, education and culture are but a few. Likewise, Stephanie Coontz, who has written extensively on the marriage and the family has recently written that marriage is evolving based on the people involved.  As a court clerk, who handled marriages, I can tell you that more and more couples have opted for a quick civil ceremony rather than a church wedding because they felt that they were merely an expensive luxury to ratify what they believe already exists in their hearts. This includes a number of Catholic couples who told me that they would convalidate IF and when  they decided to have children.  The current conventional wisdom seems to be that a marriage certificate merely legally validates what the couple already believe