This seems to be quite a simple fact and I’ve heard statistics like this many times. But when I think about it, it doesn’t make a lot of sense. How do they know how many current marriages are going to end in divorce? If they’re taking a sample of marriages which have already ended, then that’s very misleading because all those people were married a rather long time ago. Are they perhaps taking a 10 year period to see who, of those who got married in that period, are already divorced. But then some of the people left over might also get divorced in the future.
Well – I did a bit of googling to find out what they actually mean by this. According to the US National Center for Health Statistics (part of the Centers for Disease Control and Prevention), in 2001 the per capita marriage rate was 7.8 marriages per 1,000 people (0.78%). (http://www.cdc.gov/nchs/fastats/divorce.htm) This means that for every 1,000 people living in the US, 7.8 marriages were performed during the year 2001, or 15.6 individuals got married. (http://www.divorcereform.org/rates.html) The divorce rate was 4.0 divorces per 1,000 people (0.40%), or 8.0 out of every 1,000 people got divorces during 2001. (http://www.cdc.gov/nchs/fastats/divorce.htm)
So what it really means is – the number of divorces per capita is over half the number of marriages per capita. That possibly makes the statistic worse than it seems at first sight because the number of divorces is based on a smaller population (assuming the US population is increasing and the number of marriages is not going down – which it does not seem to be – see http://www.divorcereform.org/98-00divorces.html). It also doesn’t, as it appears to, give you likelihood for divorce for a current marriage, because the divorce rate now is for all people who got married in the last 65 years.