Recent fertility changes in Mongolia: what can we learn from examining tempo-adjusted fertility?

ABSTRACT

Between 1990 and 2015, several post-communist countries experienced a decline in fertility, followed by a rise in the period fertility rate of roughly one child per woman. Mongolia is a good case-in-point. Its period fertility dropped further after the demise of socialism in 1990 but has increased again since 2005 and fluctuated around 3.0 children per woman in recent years. Political factors have been suggested as the explanation of these changes. This research investigates whether demographic factors also provide explanations for the period fertility changes in Mongolia. We study this through reconstructing the fertility rates, by age and birth order, from data collected by several social and demographic surveys. The fertility rates are adjusted to examine the role of tempo effects in recent fertility changes. The results show that the demographic influences, in particular childbearing postponement and recuperation, have contributed to recent changes in fertility trends and levels in Mongolia.

KEYWORDS:

• Mongolia
• quantum of fertility
• tempo effect
• childbearing postponement
• childbearing recuperation

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 The National Statistical Office of Mongolia conducted the Reproductive Health Survey (RHS) in 1998, 2003, and 2008 based on the Demographic Health Survey (DHS) methodology with financial and technical support from UNFPA, and the Multiple Indicator Cluster Survey (MICS) in 1996, 2000, 2003 and 2010 with technical support from UNICEF. However, both survey methodologies did not have significant differences and were subsequently combined as the Social Indicator Sample Survey (SISS) in 2013.

2 These were disaggregated into the rates of the respective birth order. For the first and second birth order ASFRs, no adjustments were made since all the women tended to deliver their births before age 40. For the fertility rates of age 40–44 years in the third birth order, it was assumed that the value would account for 10 per cent of overall fertility of a corresponding age group. The remaining 90 per cent was therefore allocated into the same age of the fourth and more birth order rates. Similarly, 40 per cent of the overall fertility of 45–49 age women was distributed to the third birth order ASFRs of the same age. The remaining 60 per cent was apportioned to the fourth and more order birth rates of the same age group.

3 Several model specifications were tested to see the extent to which the smoothness was acceptable without removing the valuable features showing the trends of the data. Still, the results did not show any significant improvements. The final model was chosen for its statistical parsimony.

4 The MAC is the sum of age-specific fertility rates weighted by the mid-point of each age group, divided by the sum of the age-specific rates. It is a useful measure in revealing the change in the fertility experience of women (Blanc et al., 2013; Bongaarts, 1994).

5 In Frejka's (2011) paper, ‘younger women’ are defined as those who are under 29 and ‘older women’ as those above 29.