More on Marriage Data

Divorce is becoming less popular, the world didn’t end at the end of the millennium and StatsSA makes it hard for us to draw conclusions.

Census data isn’t the most useful for understanding marriage and divorce patterns and trends. It’s available too infrequently, relies on self-reported status and only shows a snapshot of the population at a point in time without explicitly showing the change from one state to another.

The great thing about the census data is most of it is freely availably from StatsSA so you can slice and dice it and analyse it exactly how you want.

StatsSA also puts out a Marriages and divorces 2008, with the info taken directly from registrations. I don’t have access to the underlying data, but here are some snippets that can be useful to compare and contrast with popular notions in the media.

Month of Marriage
December is the most popular month to be married

It’s a huge pity StatsSA doesn’t release the raw data, as their analysis is sadly lacking in the focus on reporting absolute numbers with comparing this against a relevant denominator in a ratio. Knowing how many divorces there are for someone who has been married twice before isn’t very helpful unless we understand how many marriages of that type there are in the first place. Knowing how many divorces involved children doesn’t help really unless we know how many marriages at that point in time were in a family with children. This tells us nothing about the relative likelihood of divorcing with or without kids.

I’ve tried to piece together some of this by comparing this transition data with the snapshot data from the census, but I have concerns that inconsistencies between the data sets may be skewing the results enough to limit their usefulness.

I’ve left out civil unions for no reason other than there is too late to analyse reliably.  There were only 80 in 2007, growing significantly to 732 in 2008, but still too few to draw conclusions on.

About Marriage

Age at First Marriage

Unsurprisingly, bride and groom are older when marrying for the second time
  1. 80% of bridegrooms are older than their brides when the brides and spinsters of widows. Nearly half of bridegrooms are younger than their brides then the brides are divorcees. Typically around 85% of widowers marry younger women, and this drops to only  just below 80% when the bride is a divorcee. A similar pattern occurs when the bridegroom is a divorcee.
  2. The ages of both bride and bridegroom for customary marriages are 2 to 3 years younger than marriages overall.
  3. There were approximately 180,000 marriages registered in 2007, when the national census estimated their to be 20.9m unmarried people between the ages of 16 and 80 (a crude assessment of most common marrying ages. Ideally we should look at rate of marriage per age band since this will definitely not be the same across all ages). Given that two people are needed to get married, this gives us 180,000 marriages out of 10.45m pairs (ignoring male:female ratios differences) which is an average marriage rate per year of 1.7%.
  4. The number or marriages has been increasing almost every year from 140,000 in 1999 to 186,000 in 2008, which translates to a growth rate of around 3% per annum while our population growth over the same period is estimated by StatsSA to be a little more than 1%. From the graph below you can see a marked jump from 2001 to 2002. The growth rate excluding that jump is more like 0.9%, slightly below the average population growth rate.
Number of marriages per year
What happened in 2002 that suddenly made everyone want to get married? World didn't end after all? Or some processing/data error. Maybe you should check that you are actually married if you were married in the last years of the previous millennium.

About Divorce

Age at divorce by population group

  1. There were about 30,000 divorces in 2007, the same year the national census put the total number of married people as 10.7m. This translates to a divorce rate of just under 0.3% (or 3 divorces per 1000 marriage) per annum. That puts us about the same as the UK. Certainly makes me question the common wisdom that 1 in 2 marriages end in divorce. Using these figures suggests to me less than 1 in 3, maybe as low as 1.5, depending on whether the age of first marriage keeps increasing and what happens to life expectancy.
  2. The number of divorces per year has been declining more or less steadily, from 37,000 in 1999 to just under 29,000 in 2008.
  3. The StatsSA report doesn’t show number of marriages by population group, but the census shows 2.1m married white citizens and  6.8m married black citizens. The number of divorces is about equal in 2008, having declined from 14,785 in 1999 to 9,481 in 2008 for the white population but having significantly increased from 6,823 in 1999 to 10,110 in 2008 for the black population. Clearly very different population dynamics at work here, or serious problems with at least one of these data sets.

So what is really happening with marriage and divorce in South Africa?

These results confuse me. Yes, there is a slight increase in age at marriage, but divorce seems to becoming less popular and with mixed messages about marriage depending on what the 2001 jump is all about.