Or do they?

Nationwide, about half of all marriages end in divorce.

via Movement under way in California to ban divorce – Yahoo! News.

I’m really sick of hearing this “fact” being passed around. Fortunately the AP article cited a source for this data so that I can attack the reporter’s stupidity:

* Number of marriages: 2,162,000

* Marriage rate: 7.1 per 1,000 total population

* Divorce rate: 3.5 per 1,000 population (44 reporting States and D.C.)

Source: Births, Marriages, Divorces, and Deaths: Provisional Data for 2008, table A

via FASTSTATS – Marriage and Divorce.

So, let’s see… 3.5 divided by 7.1 gets you 49%! Half of all marriages end in divorce.

Let’s try that with some other numbers:

• Number of births: 4,265,555
• Number of deaths: 2,426,264

2.4 divided by 4.3 gets you 56%! Over half of all births end in death.

Of course, the reality is that 100% of all births end in death, and there’s no simple statistic you could calculate for divorce.

Here are some descriptive statistics that you could try to get:

• For all marriages that occurred in 1980, what percentage were still intact, ended in death, or ended in divorce in 2005?
• For all people who died in 2000, what percentage were ever married and what percentage were ever divorced?
• For all divorces that occurred in 1995, what were the mean and decile number of months/years the marriages lasted?

But what does any of this mean for your marriage? Probably nothing.