You'll be aware that the shocking rise in inequality in the US is being used as the justification for all sorts of nonsense: from something must be done all the way to this is something therefore let's do this. The problem is with the initial statement: that inequality has risen. For it isn't actually obvious that it has. The reason being one of those little points that I bang on about so often: the results of your measurements depend entirely upon what it is that you're measuring.