One sentence summary for this book: extractive political power have limited incentives to provide the people it rules a better life, and thus are doomed to fail in the long run. Only by shifting the power to the lower class and giving them a voice can a nation succeed.
Good book with interesting case studies. One thing that I remember was about the president of Zimbabwe (forgive me if I misremembered the country) winning the national lottery of 1 million dollars, even though he already had billions. What a coincidence.