For me, the most interesting part of this book was the discussion of the new super-wealthy. Not necessarily how they lived, or how/why they were so much wealthier than the plain-old-regular rich people just under them, but how globalization has really changed the way that these people get rich. It compares our current economic environment globally with the industrial revolution and the gilded age, and makes a strong case that the growing global (and American) income inequality gap is a bad thing.
Particularly interesting was a great argument for how as historical income inequality rises, social mobility falls. The successful class creates artificial moats to protect themselves, stifles innovation and always leads to economic failure. The example of La Cerrata in Venice was very interesting - I'd like to read more on that but a quick search came up pretty empty.
There were two fantastic quotes that I flagged. The first one is Thomas Jefferson:
We have no paupers, the great mass of our population is of laborers. Our rich, who can live without labor, whether manual or professional, being few and of moderate wealth. Most of the laboring class posses property, cultivate their own lands, have families, and from the demand for their labor are able to exact from the rich and the competent such prices as enable them to be fed abundantly, clothed above mere decency, to labor moderately and raise their families. The wealthy on the other hand, and those of their ease, know nothing of what the Europeans call luxury. They have only somewhat more of the comforts and decencies of life than those who furnish them. Can any condition of society be more desirable than this?
And then 100 or so years later, from Mark Twain:
In America, nearly every man has his dream, his pet scheme, whereby he is to advance himself socially or pecuniarily. It is a characteristic that is both bad and good, for both the individual and the nation. Good, because it allows neither to stand still, but drives both forever on toward some point or other which is ahead - not behind, nor at one's side. Bad, because the chosen point is often badly chosen, and then the individual is racked. The aggregations of such cases affects the nation, and so is bad for the nation. Still, it is a trait which is of course better for people to have, and sometimes suffer from, than to be without.