Across the world, populations have transitioned to inhabiting urban spaces, and in low- and middle-income countries the proportion of people living in cities is expected to continue to increase. Anticipation of this fundamental process calls for a better understanding of the demographic factors that drive the urban transition. By indirectly estimating the joint contribution of migration and administrative reclassification to urban transition in 129 countries using urban and rural population by age and sex data available from the United Nations over 1985–2015, we find that differences in natural increase between the rural and urban sectors explain most of the urbanization over the 30-year period examined. Over the urban transition, the role of migration and reclassification declines and becomes negligible. Despite data limitations, we confirm that it is misleading to view migration as fueling urbanization in low- and middle-income countries.

中文翻译：

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低收入和中等收入国家的移民不再推动城市化（1985-2015）

在世界范围内，人口已经过渡到居住的城市空间，在低收入和中等收入国家，居住在城市的人口比例预计将继续增加。对这一基本过程的预测要求更好地了解推动城市转型的人口因素。通过使用联合国 1985-2015 年按年龄和性别分列的城市和农村人口数据，间接估计 129 个国家移民和行政重新分类对城市转型的联合贡献，我们发现农村和城市部门之间自然增长的差异解释了所考察的 30 年期间的大部分城市化。在城市转型过程中，迁移和重新分类的作用下降并变得可以忽略不计。尽管数据有限，