The Effects of Mortality on Fertility: Population Dynamics After a Natural Disaster

Abstract

Understanding how mortality and fertility are linked is essential to the study of population dynamics. We investigate the fertility response to an unanticipated mortality shock that resulted from the 2004 Indian Ocean tsunami, which killed large shares of the residents of some Indonesian communities but caused no deaths in neighboring communities. Using population-representative multilevel longitudinal data, we identify a behavioral fertility response to mortality exposure, both at the level of a couple and in the broader community. We observe a sustained fertility increase at the aggregate level following the tsunami, which was driven by two behavioral responses to mortality exposure. First, mothers who lost one or more children in the disaster were significantly more likely to bear additional children after the tsunami. This response explains about 13 % of the aggregate increase in fertility. Second, women without children before the tsunami initiated family-building earlier in communities where tsunami-related mortality rates were higher, indicating that the fertility of these women is an important route to rebuilding the population in the aftermath of a mortality shock. Such community-level effects have received little attention in demographic scholarship.

Fertility after natural disaster: Hurricane Mitch in Nicaragua

“…Similar to the earthquake studies, this examination found elevated fertility rates in the disaster zone one to four years following the tsunami (Nobles et al, 2015). This study also found strong evidence to support the idea that the death of one’s child prompts a higher fertility response.…”

“…This theory becomes more relevant in the event of family member deaths, particular one’s own children. Strong empirical evidence for replacement theory was found in a study of the 2004 Indian Ocean Tsunami and from post-earthquake fertility research in India, Pakistan and Turkey (Finlay, 2009; Nobles et al, 2015). …”

“…There are, however, natural and human-caused events that can disrupt fertility, especially in the short-term and perhaps longer. Acute natural disasters including earthquakes and subsequent tsunamis (e.g., Carta et al, 2012; Hamilton, Sutton, Mathews, Martin, & Ventura, 2009; Nobles, Frankenberg, & Thomas, 2015), severe storm events (e.g., Buekens, Xiong, & Harville, 2006; Tong, Zotti, & Hsia, 2011), as well as anthropogenic war and acts to elicit terror (e.g., Agadjanian & Prata, 2002; Blanc, 2004; Heuveline & Poch, 2007; Lindstrom & Berhanu, 1999; Rodgers, John, & Coleman, 2005) force couples to reassess fertility timing and impede access to family planning services. More germane to this investigation, several post-hurricane fertility studies, all conducted in the United States, have found both fertility increases and decreases following storm events (Cohan & Cole, 2002; Evans, Hu, & Zhao, 2010; Hamilton et al, 2009).…”

Shocks and migration in Malawi

“…Existing research on shocks and migration has typically examined large-scale shocks that affect a large population or geographic area, such as economic crisis (Curran, Meijer-Irons, and Garip 2016;Green and Winters 2010;Martin 2009) or natural disasters like Hurricane Katrina or the 2004 Indian Ocean tsunami (Fussell, Sastry, and VanLandingham 2010;Groen and Polivka 2010;Nobles, Frankenberg, and Thomas 2015). This research often focuses on differences in shock responses by socioeconomic status (e.g., Curran, Meijer-Irons, and Garip 2016;Green and Winters 2010;Martin 2009;Nobles, Frankenberg, and Thomas 2015).…”

“…This research often focuses on differences in shock responses by socioeconomic status (e.g., Curran, Meijer-Irons, and Garip 2016;Green and Winters 2010;Martin 2009;Nobles, Frankenberg, and Thomas 2015). For instance, evidence from the Irish famine in the 1840s shows that those who had the financial means to emigrate to the United States and mainland Europe survived at remarkably higher rates than those who remained in Ireland (Ó Gráda and O'Rourke 1997).…”