The relationship between levels of social and economic inequality and demographic changes remains poorly documented, particularly for fertility. Covering a period from 1986 to 2018, this paper documents a positive country-level association between income inequality and the dispersion of first birth schedules among women from 88 countries of the Global South. This association is driven by a dual dynamic of the decreasing mean age at first birth among a shrinking group of women who transition to motherhood early, and the increasing mean age at first birth and rising heterogeneity in the timing of childbearing among a group of first birth delayers. We show that this association is strongest in countries where the total fertility rate is below 2.5 children per woman. We argue that differential opportunities for accessing quality education, formal labor markets, and migration are potential drivers of the rising heterogeneity in the ages at which women transition to childbearing. These results highlight the importance of examining societal and demographic processes jointly and clearly indicate that more and better-quality data on social and economic inequality are needed.

中文翻译：

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收入不平等和全球南方向第一次生育过渡的日益分散

社会和经济不平等程度与人口变化之间的关系仍然鲜有记载，特别是在生育率方面。本文涵盖 1986 年至 2018 年期间，记录了收入不平等与来自全球南方 88 个国家的女性首次生育计划的分散之间的国家层面正相关关系。这种关联是由双重动力驱动的，即越来越多的早产女性群体平均初产年龄下降，而初产女性平均初产年龄增加，生育时间异质性增加。拖延者。我们表明，在总生育率低于每名妇女 2.5 个孩子的国家，这种关联最为强烈。我们认为，获得优质教育的机会不同，正规劳动力市场和移徙是妇女过渡到生育年龄的异质性上升的潜在驱动因素。这些结果强调了联合研究社会和人口进程的重要性，并清楚地表明需要更多和更好质量的关于社会和经济不平等的数据。