Abstract: Drawing on data from the 2008 Chinese Internal Migration and Health Survey,we compare various health indicators among rural residents who never migrated,return migrants,current rural-to-urban migrants,and urban residents.Two health selective mechanisms,the healthy migrant hypothesis and the salmon bias hypothesis,are empirically tested.Results provide empirical support to both these hypotheses.After controlling for individual’s age,sex,socioeconomic status and major health-related behaviors,rural-to-urban migrants are better off than rural residents who never migrated regarding their self-rated general health,chronic medical conditions,self-perceived physical discomforts and lung capacity.Current rural-to-urban migrants are also less likely to have chronic diseases or to report physical discomforts than return migrants.Except for self-reported chronic conditions and abnormally high heart rate,there is no significant difference in health status between rural-to-urban migrants and urban residents.

Keywords: Internal Migration, Health Selection, Healthy Migrant Hypothesis, Salmon Bias Hypothesis

摘要： 利用2008年中国流动与健康调查数据,对农村留守人口、农村外出返乡人口、乡城流动人口以及城镇居民等不同流动特征群体之间的健康差异进行比较,并系统检验了我国人口流动过程中的两种健康选择机制——"健康移民"(healthy migrant)效应和"三文鱼偏误"(salmon bias)效应。模型分析结果表明,我国人口流动存在着较为明显的"健康移民"和"三文鱼偏误"选择效应。在控制被访者的年龄、性别、主要社会经济特征以及相关健康行为后,流动人口自评一般健康、慢性病状况、经常性身体不适和肺活量等健康指标显著优于农村留守人口,乡城流动人口患有慢性病和出现经常性身体不适的可能性也显著低于农村返乡人口。在控制相关变量后,乡城流动人口与城镇居民的健康状况(除慢性病和心率过高症状外)不存在显著差别。

关键词: 人口流动, 健康选择, 健康移民假说, 三文鱼偏误假说