机会平等哲学下对我国农民工“健康移民效应”的再考察

HIE Meets EOP:Reexamination of“Healthy Immigrant Effect”of Migrant Workers in China under the Framework of the Equality of Opportunity

“健康移民效应”是指相比于本地居民,移民的健康状况更好。本文使用RUMiC 2008和2009数据,发现外出农民工心理健康状况比城市居民更差。为剖析我国现实与“健康移民效应”这一典型事实相矛盾的原因,本文将“机会平等”哲学理念与“健康移民效应”相结合,在新构建的框架下进行了分解研究,结果显示:按照合理的“努力特征效应”来看,外出农民工本该比城市居民更健康(GHQ值小0.145),即我国农民工的“健康移民效应”本该存在,但严重的机会不平等拉低了他们的心理健康水平(GHQ值大了0.257),最终导致外出农民工的心理健康水平反倒比城市居民更差(GHQ值大了0.112)。此外,外出农民工的心理健康状况好于从未外出的农村居民,也好于回流的农民工,这表明农民工的外出和回流存在“自选择”机制。但这些自选择机制主要是合理因素在起作用,而不是机会的不平等。

A key stylized fact that is generally supported in the literature is the Healthy Immigrant Effect(HIE),which means immigrants are healthier than their native counterparts.Using the nationwide data of RUMiC2008-2009,this paper finds a conflict between the results of the descriptive statistic and the regression.Therefore,we use the Theory of the Equality of Opportunity(EOP)to decompose the HIE to identify the reason for the conflict.The results show that,according to the legitimate“effort characteristic effects”,migrant workers are supposed to have a better mental health level than the native urban residents(0.145 unit),but inequality of opportunity leads to a decrease of 0.257 unit in terms of mental health.Ultimately,migrant workers have a worse mental health level than the native urban residents(0.112 unit).In addition,the mental health level of migrant workers is better than the non-migrant rural residents and the migrant workers who returned home.This reflects the self-selection migrant effects and the salmon effects.The main reason for the two effects is the legitimate“effort characteristic effects”rather than the inequality of opportunity.