Healthy migrant and salmon bias hypotheses: a study of health and internal migration in China

Soc Sci Med. 2014 Feb;102:41-8. doi: 10.1016/j.socscimed.2013.11.040. Epub 2013 Nov 28.


The existing literature has often underscored the "healthy migrant" effect and the "salmon bias" in understanding the health of migrants. Nevertheless, direct evidence for these two hypotheses, particularly the "salmon bias," is limited. Using data from a national longitudinal survey conducted between 2003 and 2007 in China, we provide tests of these hypotheses in the case of internal migration in China. To examine the healthy migrant effect, we study how pre-migration self-reported health is associated with an individual's decision to migrate and the distance of migration. To test the salmon bias hypothesis, we compare the self-reported health of migrants who stay in destinations and who return or move closer to home villages. The results provide support for both hypotheses. Specifically, healthier individuals are more likely to migrate and to move further away from home. Among migrants, those with poorer health are more likely to return or to move closer to their origin communities.

Keywords: China; Health; Healthy migrant; Internal migration; Return migration; Rural–urban migration; Salmon bias.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Bias*
  • China
  • Diagnostic Self Evaluation
  • Emigration and Immigration / statistics & numerical data*
  • Female
  • Health Status*
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Transients and Migrants / statistics & numerical data*
  • Young Adult