Fertility and immigration: Do immigrant mothers hand down their fertility pattern to the next generation? Evidence from Norway
基于挪威1935-1995年123国移民登记数据，研究发现移民母亲原籍国生育率每增加1，其1.5代和2代女性子女数平均增加0.12-0.14，但代际间生育率下降，未来移民背景人口增长可能放缓。
We examined whether the fertility pattern of immigrant mothers is handed down to the next generation. Our analyses were carried out on population register data. These data contained information on all immigrants to Norway from 123 countries during the period 1935-1995. We examined whether there was a relationship between the fertility rate in the country of origin and the number of children for generations 1.5 and 2 in Norway. We estimated three models: fixed effects for country of origin, fixed effects for region, and no fixed effects. The three specifications yielded estimates with overlapping confidence intervals. We interpret the estimates from the models with fixed effects for region, and the model with no fixed effects as upper-bound estimates. They show that an increase of 1.00 in the fertility rate in the country of origin leads to an average increase in the number of children of 0.12 (no fixed effects) or 0.14 (fixed effects for region) for immigrant women in generations 1.5 and 2. The estimate from the model with fixed effects for country of origin was small and not statistically significant at the conventional level. We interpret this as a lower-bound estimate. Our upper-bound estimates for generations 1.5 and 2 are smaller than the estimates for generation 1, i.e. there has been a decrease in the fertility rate from the first to the second generation. As a result, if the proportion of the population with an immigrant background continues to increase, it may increase at a slower rate in the future.