I just completed The Spirit Level by Richard Wilkinson & Kate Pickett.   In a world where rising tides supposedly lift all boats and supposedly left-wing parties are afraid to campaign on increasing taxes on the wealthy for fear of being accused of "class warfare", this book is a breath of fresh air.  Chapter by chapter, it shows how wealth inequality is linked to societal mistrust, mental and physical health problems, obesity, poor educational performance, teenage pregnancies, increased violence, and higher levels of imprisonment.  These manifestations are higher not just in the poorer segments of unequal societies but in the wealthier ones as well.  In the final chapters, it ties everything together to implicate wealth inequality as the most likely cause of these societal problems.

This is a book that needs to be read by people in the halls of power.