[DHAKA] Economic development may be the key driver of reducing family size and thus slowing population growth, according to researchers looking at data from Bangladesh.
Developments such as educating women, shifting from agricultural work and increasing wage labour are related strongly to fertility decline, they report in a study published last month (14 May) in Proceedings of the National Academy of Science (PNAS).
They say the finding could help design policies to influence fertility decisions. The world's population is predicted to continue to grow by 2050, putting more strain on development and need for resources, such as water, food and energy, especially in Africa and Asia.
The study set out to test explanations for demographic transition — a global phenomenon in which high birth and death rates are replaced by low ones as countries develop.
Bangladesh has had a rapid, recent demographic transition. For example, the number of children born per woman in the Matlab subdistrict fell from 6.7 to 2.6 between 1966 and 2010.
The scientists conducted a survey in 2010 and combined it with data collected since 1966 from approximately 225,000 people.
They looked at 64 variables corresponding to three explanations of demographic transition: risk and mortality (as infant mortality drops parents switch to having fewer children); economic and investment (the more parents invest in a child, the better off the child will be); and cultural transmission (fertility is a social norm that spreads from elites to the rest of society).
They found that the variables linked to the economic and investment explanation were much stronger predictors of fertility or family size.
"Our study suggests that focusing on education and economic development is probably the most effective way to motivate people to reduce fertility," says Mary Shenk, the lead researcher and an anthropological demographer at the University of Missouri, United States.
"If families perceive that their children have educational opportunities and jobs, then they are likely to focus on investing in a smaller number of children who will be able to get those jobs," Shenk tells SciDev.Net.
Nurul Alam, a coauthor from Bangladesh's International Center for Diarrhoeal Disease Research, says that educated women may also learn social norms favouring fewer children, and be more aware of the need to invest in education to prepare children for good jobs.
Ubaidur Rob, Bangladesh director of the Population Council, a research think-tank, says that although education does affect fertility, educated and non-educated women in Bangladesh are using contraceptives at the same level in low-fertility areas.
"Migration to urban areas also contributes to fertility decline as women get involved in paid employment," he says.
The study also found support for the two other explanations, suggesting that fertility decline is caused by many factors.
Link to study abstract in PNAS
PNAS doi: 10.1073/pnas.1217029110 (2013)