A recently published book entitled The Spirit Level: Why More Equal Societies Almost Always Do Better, has produced the evidence that will no longer allow anybody to legitimately claim that income inequality doesn't matter. Written by Richard Wilkinson and Kate Pickett, this book addresses key issues concerning how inequality and/or income inequality cause the levels of health and other social indicators: levels of trust, mental illness, life expectancy, infant mortality, obesity, educational performance, teenage prgnancy, murder rates, imprisonment rates and social mobility. An excellent review article is available at the Citizen's Income Trust website and can be accessed here.