by Elizabeth Rogers
Freakonomics Radio is an ongoing podcast series by the authors of the book of the same name Steven Levit and Steven Dubner and economist and journalist respectively. Their mission is to examine the hidden side of everything. In one of their recent pieces took on the question of why we have children. One of their guests for this piece was Elizabeth Frankenberg, a demographer and sociologist who has studied population dynamics in Indonesia for more than twenty years. On boxing day, December 26th, 2004 a 9.1-magnitude earthquake off the coast of Sumatra struck. It created massive tsunami waves throughout the region. After the devastation caused by the tsunami, she and her colleagues focused their research on the fertility rates in the affected regions. A small silver lining in the wake of events such as the tsunami is that is allows researchers to gather data to answer questions they would not normally be able to.
The research was examining the population dynamics in the wake of these mass mortality events. They hypothesized that there would be link between the fertility and mortality rates in areas affected by the tsunami, and the data seems to support this. While the research is ongoing, in their working paper published by the National Bureau of Economic Research, they reported that among the women who lost a child in the tsunami, were approximately ten percentage points more likely to have another birth after the tsunami than those women whose children had survived. This translates into a 37% increase. This was clear evidence in support of the theory that mortality and fertility are linked.
Their research also examined if the age of the child had any statistically significant affect and other possible factors. What they found was that communities that were affected by the tsunami had drastically different fertility rates after words than those that were not. Not only were women who lost children more likely to give birth after the tsunami, but so were women who had not had a child at all prior to the tsunami. They hypothesized that this was due to a community sentiment to rebuild as well as the fact that many new unions were formed after the tsunami.
Men were more likely to have survived they went on to form new marriages and from these new marriages came the increase in birth rates among women who had not yet given birth. This demonstrated what the researchers saw as a collective desire to rebuild the community.
This type of research allows us to understand the fundamentals of population rebuilding. It also offers a new lens though which to see the relationship between mortality and fertility. This study in particular can help researchers understand the long term affects of disasters such as the tsunami on population demographics, family planning and what these will mean for the region. All of which can be powerful informational tools for organizations working in disaster preparedness and recovery.