US is also a super bad infant mortality rate compared to other countries:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4856058/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5844390/
Access to healthcare is quite low in the US compared to most of the 50 countries ahead of us. We also have higher levels of poverty, ESPECIALLY for a lot of parents/children.
GDP is irrelevant. The paper says:
> In 2013, the US infant mortality rate (IMR) ranked 51st internationally, comparable to Croatia, despite an almost three-fold di erence in GDP per capita
If you have high GDP per capita, and more poor people per capita, and health care is not free - you're going to have more people not accessing health care and suffering the consequences.
In this world - I would expect infant mortality to be much higher even when the healthcare systems are equal.
> Consistent with past evidence that has focused on comparing the US with Scandinavian countries, we find that birth weight can explain around 75% of the US IMR disadvantage relative to Finland or Belgium. However, birth weight can only explain 30% of the US IMR disadvantage relative to Austria or the UK