IIASA research shows that increasing access to clean energy can rein in population growth, and so reduce future energy needs. Another study finds that falling fertility does not have to be bad news for economies.

Hundreds of millions of households still lack electricity, and billions cook over open fires, so we must improve access to clean energy. One potential concern was that this would raise energy demand and so accelerate climate change. A recent study led by IIASA researchers, however, shows otherwise.

“In fact, increasing energy access for poorer populations can reduce population growth and so decrease energy demand,” says Roman Hoffmann, a researcher in the Migration and Sustainable Development Research Group of the IIASA Population and Just Societies Program.

Hoffmann and his team analyzed demographic and health surveys spanning 1990 to 2015, in which women were asked questions including their energy use and family size. The authors found a strong connection, even after controlling for other factors such as changing incomes and urbanization. Total fertility (the average number of live births per woman) falls by 0.018 for each one-percent increase in access to electricity, and by 0.013 for each one-percent increase in access to clean cooking.

There are probably several reasons behind this. For example, pollution from solid fuels contributes to high child mortality, which may encourage parents to overcompensate and have many more children; while electricity brings access to modern media, helping to inform women about reproductive and other life choices. The team found that access to television has been particularly important, accounting for a third of the effect of electrification.

While previous studies have examined links between electricity and fertility, this is the first to include the effect of cooking fuels. It is also far more detailed, looking at the relationships across many countries at a subnational level. It shows that the effects are much stronger where fertility rates are high, for example, in much of sub-Saharan Africa. Improving energy access, especially in those regions, could therefore aid climate mitigation as well as having benefits for poverty, health, and equality.

While falling fertility is clearly good news for the environment, there is a concern that it could be a “demographic time bomb” for economies. The story goes that as birth rates drop and populations age, fewer workers must financially support more retirees. This view is embodied in a measure called the age dependency ratio: the number of people aged 0-14 and 65+, divided by the number between 15 and 64. It is however simplistic to assume that everyone of working age is an equal asset and everyone else a burden, says Guillaume Marois, a researcher in the Multidimensional Demographic Modeling Research Group.

He and his colleagues have developed new demographic indicators that also take into account changing education and participation in the labor force, as well as their effects on productivity.

“New cohorts of workers will be much more educated than those who retired, so they are likely to be much more productive,” says Marois. “This change in the productivity of the working force could largely avoid the widely expected negative impacts of aging.”

Applying these measures to China, the researchers see an optimistic future. Even assuming very low fertility levels, economic dependency remains fairly level out to 2070.

"Although demographic aging is unavoidable, the fears associated with the coming economic burden have been exaggerated," concludes Marois.