Indeed, international comparison of social mobility corroborates this reasoning. According to a careful study by a group of researchers in Scandinavia and the UK, the Scandinavian countries have higher social mobility than the UK, which in turn has higher mobility than the US. It is no coincidence that the stronger the welfare state, the higher the mobility. Particularly in the case of the US, the fact that low overall mobility is largely accounted for by low mobility at the bottom suggests that it is the lack of a basic income guarantee that is preventing poor kids from making use of the equality of opportunity.