![Nature | V Moos/Corbis/Getty](https://ifp.nyu.edu/wp-content/uploads/2024/05/1-51.jpg)
Nature | V Moos/Corbis/Getty
Where should society draw the line on extreme wealth? A fresh account sets out the logic and suggests how to redress inequality. Above: In Rio de Janeiro, Brazil, residents in unplanned settlements live just blocks away from wealthy suburbs.