I've pointed out several times how the "50% of all marriages end in divorce" stat is problematic due to the bias of the repeat failure in the numbers; i.e., some guy who has 5 marriages that all end in divorce is counted as five failures in the stats, while one couple who is married for 65 years counts as 1 good marriage.
However, I didn't have any other source to show how powerfully that biases the result until I saw this today in the WSJ's Real Time Economics blog:
[i] September 19, 2007, 2:00 pm
Has Marriage Rebounded?
After a years-long slide, the decline in the length of marriages has slowed down and even shown signs of an uptick, according to the U.S. Census Bureau.
People still have shorter marriages than they did in the 1950s the number of couples that make it to their 10th anniversary has fallen steadily for couples married after 1959: Men married between 1955 and 1959 made it to their 10th anniversary 90% of the time, while men married between 1970 and 1974 made it 73% of the time.
Changes in the law, and greater social acceptance of divorce, are largely blamed for the increase in divorces. Divorce rates jumped in the early 1970s, just as divorce got easier.
Since then marriages have for the most part held steady, and in some cases increased. Men and women married between 1975 and 1979 saw only a slight decrease in longevity, while those married between 1985 and 1989 made it to their 10th anniversary 75% of the time. The proportion of people making their 5th and 15th anniversaries also appears to have stabilized.
The marriages could end in either death or divorce. And while Americans have been getting married later in life, stabilizing divorce rates appear to be the driving factor.
Note it's not a perfect corrolation of the measurements, but I think we can safely assume those who are married for 10 years have a much reduced likelihood of getting a divorce (much like life-expectancy statistics can be severely impacted by infant mortality rates).
So, all things being equal, the average person entering a marriage has a 75% chance of making it to the 10th anniversary. That seems to be to be a fairly stark contrast to claims that the average marriage has a greater than 50% chance of ending in divorce...