中文摘要：

一个国家的人口性别结构主要由出生人口性别比、死亡人口性别比、国际迁移人口性别比共同决定。中国并非移民国家,人口性别比结构主要由出生人口性别比和死亡人口性别比共同决定。本文利用各年普查数据进行估算和预测,构建连续的出生队列并以此数据对我国人口性别结构进行分析。研究认为中国人口性别比长期持续偏高,而在我国的生育文化特征下女性人口在低龄组更容易被瞒报,所以统计数据的瞒报、漏报在一定程度上夸大了低龄组人口性别比偏高的程度,但不能把瞒报、漏报认定为性别比偏高的主因。根据生物学一般规律,在同等客观条件下男性的死亡概率在任何年龄均高于女性,总体上同一出生队列的人口从出生到进入婚龄,男性死亡人口规模大于女性,所以婚龄人口性别比在没有国际人口迁移影响的前提下必然要小于出生人口性别比。低年龄组死亡人口性别比对于婚龄人口性别比具有重要影响,但由于科技进步和医疗水平的提高,死亡率不断降低,死亡人口性别比不会给婚龄人口性别比带来决定性的影响,不会改变出生人口性别比偏高会导致婚龄人口性别比偏高的基本事实。通过对2020年婚龄人口相应出生队列的分析,认为无论采用哪种数据来源和方法计算,持续偏高的出生人口性别比必然会导致婚龄人口性别比失衡,进而导致一系列的社会、经济以及文化问题。

英文摘要：

Population sex-structure is mainly decided by sex ratio at birth, sex ratio of deaths, and sex ratio of international migration. Since China is not an immigration country, the sex-structure of China mainly decided by sex ratio at birth and sex ratio of deaths. By using various census data to estimate and forecast, this article constructs continuous birth cohorts, and analyzes the sex-structure of China. The paper concludes that the sex ratio of China keeps sustainable high for a long term, owing to fertility culture in China, there are more false reports and omissions in low-age female groups, and the statistical data exaggerate the height of sex ratio to a certain extent. But we cannot decide these false reports and omissions to be the main reason of the high sex ratio. On the basis of general biology rule, mortality is higher in male than in female at any age under the same objective condition. As a whole, the male death scale is larger than female death scale in same birth cohorts from birth to marriageable age. According, without international migration, sex ratio of marriage age is bound to be lower than sex ratio at birth. However, because of the progress of science and the improvement of the medical treatment, the mortality rate is decreasing. Sex ratio of deaths in low-age groups has important effect on the sex ratio of marriage age population, but will not change the basic fact that high level sex ratio at birth will lead to marriage squeezes. Base on the analysis of marriage cohorts in 2020, the article concludes that no matter what kind of data sources and methods we use, it is deterministic that constantly high sex ratio at birth will lead to unbalance of sex ratio of marriage age population, then lead to series of social, economic, and cultural issues.