From an amazon review:<p><i>This book presents the thesis that many ills of today&#x27;s society (obesity, mental illness, rates of drug abuse, ...) can be attributed to large income inequality. The authors make this point using two-dimensional scatter plots, with income inequality on the x-axis, the prevalence of some form of social ill on the y-axis, and dots in the plot representing individual countries. These plots generally show a positive correlation between income inequality and various social ills.<p>As a statistician, I would like to comment on the soundness such argumentation: unfortunately virtually all graphs are plagued be a confusion of correlation with causation. </i><p>Reviewer then explains correlation and causation. I could claim &quot;inequality is good&quot; using the same methods. I&#x27;d argue inequality is immaterial but does tend to be correlated with poverty, which is what we should focus on.<p>Not to be outright dismissive (I should read the book), but this is a problem in social sciences in general. I think software simulations would be a lot more useful at this point than scatterplots comparing two variables used by so many economists today. I think I&#x27;ve read about people starting to do that in various areas, not sure about how prevalent it is in economic modelling. AFAIK not very.