It is not the fact that Swedes in in Malmö and Vellinge are rich that is CAUSING Rosengård dysfunctional, as Wilkinson claims. If Vellinge had an economic crisis and became poor, this would have no effect of health in Rosengård (or probably a negative effect, since the hospitals would have less money). The causality is more complex.
People in corrupt southern Italy have lower health outcomes and lower economic outcomes than North Italians. The casual link is that Mafia, lack of trust, and low education make south Italians poorer, and it makes them have lower health outcomes.
The Spirit Level thinking instead childishly interprets the complex relationship that North Italians are rich makes South Italians unhealthy, because of the stress of knowing they are doing worse than North Italy.
The country with the highest life expectancy, Japan, has the 9th highest level in inequality measured by Gini after taxes and subsidies. The Spirit Level gets around this "problem" by using a very selective measure of inequality, the ratio of two groups of people, instead of the standard measure in social sciences, Gini , which looks at every member of society, including the poor. Furthermore, they use an "index", instead of the straigtforwards measure: how long people live.
Out of the OECD countries, Wilkinson excludes 9 nations. Why do the authors include Portugal, but not Korea and Czech Republic (that are richer than Portugal), or Slovak Republic (that is as rich as Portugal)? One reason he excludes them is that Czech Republic and Slovak Republic have very even distribution of income, but low life expectancy. Portugal fits his story, it is unequal and does bad. Czech Republic and Slovak Republic don't fit the story, since they are equal and do badly?