An earlier research article, which received extensive media coverage, argued that divorce leads to a higher use of resources such as domestic energy and water (Yu and Liu 2007). Considering 12 countries around the world they found that divorce leads to an increase in the number of small, less energy efficient households. Those who live alone usually live in housing with more square feet per person than those who live as a couple. This means that two people living alone require more heating than a couple living together. In addition, some consumer durables that require electricity are consumed at the household level, such as refrigerators, freezers, TVs etc. This leads Yu and Liu to conclude that high divorce rates will entail high levels of energy consumption.
However, they fail to take into account that those who experience a divorce end up with fewer children on average than those who are continuously married. In our recent paper Christiansen and Skirbekk (2015), we use household forecasts of the Danish population to consider how domestic energy use is affected by changes in divorce rates in the short- and long-term. We take into account both the increase in the number of smaller households which are less energy efficient and the effect of lower fertility which means fewer energy consumers.
Utilising Danish register data we have detailed information about fertility by the age and household position of the mother (see Figure 1). As women who get divorced during the childbearing years usually spend some time living alone or as a single mother following divorce, and as fertility is lower in these groups than among women living as part of a cohabiting or married couple, on average, they end up with fewer children than those who are continuously married. Although many in higher order unions where there are children from earlier unions choose to have shared children to “cement” their partnership and signal their commitment to each other, a number of studies have found that those who have experienced a divorce end up with fewer children. For example, a recent study of 23 European countries found that having divorced is negatively associated with number of children for both men and women (Van Bavel et al. 2012).
Figure 1: One year birth rates by women’s household position and age, 2002-2006
We look at 5 scenarios for divorce rates: (1) a benchmark where we assume constant divorce and union dissolution rates as observed in recent years, (2) 50% higher divorce and union dissolution rates, (3) 100% higher divorce and union dissolution rates, (4) 50% lower divorce and union dissolution rates and (5) no divorce or union dissolutions.
In our projection model women are exposed to fertility rates that are dependent on age and household position, as shown in Figure 1. This means that in the scenarios with higher divorce rates, where women spend a greater proportion of the childbearing years not living in a couple household, they end up with fewer children on average.
Table 1 shows the proportion of life spent living in different household position in the 5 scenarios. the proportion of life time spent living alone varies between 10% in the no divorce scenario and 25% in the 100% higher rates scenario. On the other hand women spend between 21 and 44 per cent of their lives living with a spouse, and between 1 and 7 per cent living as a single parent. The proportion of time spent cohabiting does not vary much between the scenarios. This is a result of two opposing effects. On the one hand the increase in union dissolution rates leads to an increase in separations. On the other hand the higher proportion of divorced persons, who often choose to cohabit when they re-partner, which cet par leads to a larger proportion of life spent cohabiting.
Table 1: Percentage of life spent in different household positions under five different divorce scenarios- Women
The TFR varies between 1.71 in the 100% higher rates scenario and 2.16 in the No divorce scenario, Table 2.
Table 2: Total Fertility Rate in the different divorce scenarios
In the short run the scenarios with higher divorce rates are where we find the highest domestic energy consumption (see Figure 2). That is to say that in the short run the dominant effect is that of the larger number of smaller households, which are less energy efficient. During this time span higher divorce rates, indeed, lead to higher levels of domestic energy consumption. However, after about 40 years the effect of the smaller population in the scenarios with higher divorce rates dominates and having high divorce rates yields low domestic energy use.
Figure 2: Energy consumption (in million kilowatt hours) under five different divorce scenarios
We conclude that in the short run it is very likely that higher divorce rates would entail higher domestic energy consumption. However, in the long run higher divorce rates may well lead to a reduction in energy consumption by households.
It may be argued that a doubling of divorce rates in countries where divorce is already highly prevalent such as in Denmark is implausible. However, divorce rates are increasing in many countries around the world where divorce so far has been uncommon. In these countries divorce may have a profound impact on domestic energy use in the coming decades. In addition, earlier research has found that moving from strict to more lenient divorce laws depresses the fertility of both those who are currently married and those who are single (Bellido and Marcén 2011), which makes an even larger effect plausible in countries where divorce laws are set to become more permissive. In countries where non-marital fertility is less acceptable an increase in divorce rates may also have a more profound impact on overall fertility.
This post has been jointly written by Solveig Glestad Christiansen and Vegard Skirbekk, Senior Researcher at the Norwegian Institute of Public Health and Professor of Population and Family Health at Columbia Aging Center, Columbia University.
Bellido, H., & Marcén, M. (2013). Divorce laws and fertility decisions, MPRA Paper No. 48309, University Library of Munich, Germany;
Christiansen, S. G., & Skirbekk, V. (2015). Is divorce green? Energy use and marital dissolution. Population and Environment. DOI: 10.1007/s11111-015-0236-5;
Van Bavel, J., Jansen, M., & Wijckmans, B. (2012). Has divorce become a pro-natal force in Europe at the turn of the 21st century?. Population Research and Policy Review, 31(5), 751-775;
Yu, E., & Liu, J. (2007). Environmental impacts of divorce. Proceedings of the National Academy of Sciences, 104(51), 20629-20634.