The spirit level

The message in the book is very valid, but it could be conveyed in far fewer pages. I didn‘t finish the book, this is the key message, if you don't want to know, stop now.

Almost every negative metric in society (drug use, obesity, crime, etc.) correlates with income inequality (not average income or GDP). And the US is the clear leader on economic and societal inequality.

Every chapter highlights a specific negative metric, demonstrates a correlation with inequality and talks about how it could be causative.

Evey chapter is the same, read one chapter and you've read it all.

The only caveat is people/countries below the poverty line. People that really can't afford to eat, people struggling to survive; they do benefit from increases in average income, but the benefit stops once they are out poverty.