Last year my cousin recommended a book to me that I bought and threw on a shelf. I found it a few weeks ago as I was helping tidy for visitors! The book is called, “The Spirit Level: Why More Equal Societies Almost Always Do Better”. It is a great and thought provoking read. Here is an introduction cut/paste from a website related to the book.
1) In rich countries, a smaller gap between rich and poor means a happier, healthier, and more successful population. Just look at the US, the UK, Portugal, and New Zealand in the top right of this graph, doing much worse than Japan, Sweden or Norway in the bottom left.

2) Meanwhile, more economic growth will NOT lead to a happier, healthier, or more successful population. In fact, there is no relation between income per head and social well-being in rich countries.
3) If the UK were more equal, we'd be better off as a population. For example, the evidence suggests that if we halved inequality here:
- Murder rates could halve
- Mental illness could reduce by two thirds
- Obesity could halve
- Imprisonment could reduce by 80%
- Teen births could reduce by 80%
- Levels of trust could increase by 85%
4) It's not just poor people who do better. The evidence suggests people all the way up would benefit, although it's true that the poorest would gain the most.
5) These findings hold true, whether you look across developed nations, or across the 50 states of the USA.
I wonder how would project success rate across the countries. I wonder would countries with more income equality have less failed projects?