Jonsson Stefan Hrafn, Rendall Michael S
Icelandic Center for Social Research and Analysis, Laugavegur 58B 101 Reyjavík, Iceland.
Demography. 2004 Feb;41(1):129-50. doi: 10.1353/dem.2004.0006.
Crucial to the long-term contribution of immigration to a receiving country's population is the extent to which the immigrants reproduce themselves in subsequent, native-born generations. Using conventional projection methodologies, this fertility contribution may be poorly estimated primarily because of problems in projecting the number of immigrants who are at risk of childbearing. We propose an alternative method that obviates the need to project the number of immigrants by using the full sending-country birth cohort as the risk group to project their receiving-country childbearing. This "sending-country birth cohort" method is found to perform dramatically better than conventional methods when projecting to 1999 from base years both before and after the large increase in inflows of Mexican immigrants to the United States in the late 1980s. Projecting forward from 1999, we estimate a cumulative contribution of Mexican immigrant fertility from the 1980s to 2040 of 36 million births, including 25% to 50% more births after 1995 than are projected using conventional methods.
移民对接收国人口的长期贡献的关键在于，移民在随后的本土出生代中自我繁衍的程度。使用传统的预测方法，这种生育率贡献可能估计得很差，主要是因为在预测有生育风险的移民数量时存在问题。我们提出了一种替代方法，通过将完整的输出国出生队列作为风险群体来预测他们在接收国的生育情况，从而无需预测移民数量。当从20世纪80年代末墨西哥移民大量涌入美国之前和之后的基准年份预测到1999年时，发现这种“输出国出生队列”方法的表现明显优于传统方法。从1999年向前预测，我们估计20世纪80年代至2040年墨西哥移民生育率的累计贡献为3600万出生人口，其中1995年之后的出生人口比使用传统方法预测的多25%至50%。
