Fertility and early child bearing

Just in case you are not already tired of reading about fertility. I wrote here and here on how the high fertility rates in Nigeria are probably not driven by knowledge about birth control or female empowerment ( between husbands and wives). The two graphs below suggest they are driven by early marriage and pregnancy.


The first plots fertility rates against the percent of women aged 15-19 who have begun child-bearing. The second plots fertility rates against the median age at first birth for women aged 25 – 49. The graphs are pretty self-explanatory. States with women who start child-bearing early have much higher fertility rates that states with women who do not start so early. Again states with a higher percentage of women with teen pregnancies ( presumably because they are married early but not necessarily) have much higher fertility rates than states with a lower percentage of teenage pregnancies. For some reason the data on age of first marriage was not published for states, only published by zones. Looking at the zones tells the same story. The median age at first marriage for the north east and north west, zones with the highest fertility rates, are 15.6 and 15.2 respectively. Yes 15! It is 22.8 for the south east, the zone with the lowest fertility rate.

The story the data is telling is very logical. Women who get married early have a lot more kids than women who marry later. Makes a lot of sense. If a girl gets married at 15 then she has the opportunity to have 3 or 4 more kids before she can biologically stop giving birth than a woman who marries at 23. If you live in Nigeria you know the kind of unfair pressure women face once they get married to give birth.

I looked at the frequency of births once married too. Just to make sure it wasn’t the case that women in high fertility states were just having kids more often than women in states with lower fertility. As the graph below shows there is no discernible pattern between fertility and the frequency of child-birth once married.

The message for policy makers is this: if the goal is to bring down fertility rates then the obvious place to start is to figure out how to prevent girls from getting married early. How to do this is anyone’s guess but you probably can’t legislate it or force people to buy into the idea. You have to convince them that it is the smart / cool thing to do. Here is a hint on the kinds of things that convince people to alter their behavior. Or if you don’t want to read the entire paper you can read a summary here. It involves the love-triangles, family feuds and paternity mysteries of Brazil’s telenovelas. TV shows.

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