Asian Demographic Research Institute, Shanghai University, Shanghai, 200444, China;
Wittgenstein Centre for Demography and Global Human Capital (IIASA, VID/OeAW, WU), International Institute for Applied Systems Analysis, Laxenburg, 2361, Austria.
Proc Natl Acad Sci U S A. 2018 Aug 14;115(33):8328-8333. doi: 10.1073/pnas.1722359115. Epub 2018 Jul 30.
Within the next decade India is expected to surpass China as the world's most populous country due to still higher fertility and a younger population. Around 2025 each country will be home to around 1.5 billion people. India is demographically very heterogeneous with some rural illiterate populations still having more than four children on average while educated urban women have fewer than 1.5 children and with great differences between states. We show that the population outlook greatly depends on the degree to which this heterogeneity is explicitly incorporated into the population projection model used. The conventional projection model, considering only the age and sex structures of the population at the national level, results in a lower projected population than the same model applied at the level of states because over time the high-fertility states gain more weight, thus applying the higher rates to more people. The opposite outcome results from an explicit consideration of education differentials because over time the proportion of more educated women with lower fertility increases, thus leading to lower predicted growth than in the conventional model. To comprehensively address this issue, we develop a five-dimensional model of India's population by state, rural/urban place of residence, age, sex, and level of education and show the impacts of different degrees of aggregation. We also provide human capital scenarios for all Indian states that suggest that India will rapidly catch up with other more developed countries in Asia if the recent pace of education expansion is maintained.
在未来十年，印度的人口预计将超过中国，成为世界上人口最多的国家，这主要是因为印度的生育率仍然更高，且人口更年轻。到 2025 年，每个国家都将拥有约 15 亿人口。印度的人口结构非常多样化，一些农村文盲人口的平均生育率仍超过 4 个孩子，而受过教育的城市女性的生育率则不到 1.5 个孩子，各州之间存在巨大差异。我们表明，人口前景在很大程度上取决于人口预测模型明确纳入这种异质性的程度。传统的人口预测模型仅考虑国家一级的人口年龄和性别结构，其预测的人口数量低于在州一级应用相同模型的结果，因为随着时间的推移，高生育率的州的权重增加，从而将更高的生育率应用于更多的人。从教育差异的明确考虑中得出的结果则相反，因为随着时间的推移，生育率较低的受过更多教育的女性比例增加，从而导致预测增长率低于传统模型。为了全面解决这个问题，我们按州、城乡居住地、年龄、性别和教育水平构建了印度人口的五维模型，并展示了不同聚合程度的影响。我们还为所有印度州提供了人力资本情景，表明如果保持最近的教育扩张速度，印度将迅速赶上亚洲其他更发达的国家。
