Many studies have investigated the "migrant mortality advantage" – the notion that international migrant populations have lower death rates than non-migrant populations. This may be because those who migrate are selected, i.e. they have better average health as well as characteristics associated with better health, such as income and education level. However, because previous research has almost always focused on comparing migrant populations to the non-migrant population in the country of destination, due to a keen interest in migrants’ experiences and roles in their new country, there is little evidence to show that migrants are selected. Consequently, Matthew Wallace and Ben Wilson of the Stockholm University Demography Unit (SUDA) focus on comparing death rates among migrant populations to death rates in the origin country.
Using data on 35 migrant groups living in England and Wales, and drawing from several international databases to collect origin country mortality data, the authors looked at relative death ratios by comparing migrant group death rates with death rates in their origin countries between 2010 and 2012. Around half of the groups in the sample originate from countries at similarly high levels of development to the country of destination, while the other half originate from medium- or less-developed countries. They also account for age as well as separately investigating migrants’ educational advantage in their analysis.
Wallace and Wilson find that the migrant mortality advantage relative to the origin country is present in nearly all groups, but its size depends on the development level in the origin country. Migrants originating from countries that neighbor England and Wales or feature similar levels of development, including Canada, Hong Kong, and Ireland, do not enjoy lower death rates than those who remain in the origin country. In general, the lower the development level of the origin country, the greater the size of the advantage of migrants in the destination country. Advantages were often largest at young adulthood (just after many migrants tend to arrive) and diminished with age and length of stay. The authors also find a persistent educational advantage for almost all migrant groups, which may help to explain their mortality advantage.
Such a study focusing on migrant mortality advantage versus origin country gives us valuable insights in ways that comparisons to non-migrants in the destination country cannot. For one matter, for the first time for such a large and diverse range of migrant groups, Wallace and Wilson show strong evidence consistent with selection as the main explanation of the migrant mortality advantage. Additionally, such findings help to rebalance discussion regarding the impact of migration on mortality and health beyond the country of destination. Additional research could investigate what patterns of advantage shape selection into migration based on health as well as life course trajectories after arrival in the destination country.