American economist Thomas Sowell remains, in my view, one of the "must-read" authors for folk interested in the case for liberal markets and critiques of well-intentioned but hubristic social policy. In one of his books, The Vision of the Anointed, he hits upon a key fact that is so often ignored by writers making statements such as "X percent of the population own Y percent of the wealth", and then proceed, in terms of great indignation, to argue for massive redistribution of wealth to rectify said terrible state of affairs. Sowell points out that what such statements miss out is that we are all getting older, our lives change, and as we do so, it is common for folk to pass from one wealth bracket to another:

"One common source of needless alarm about statistics is a failure to understand that a given series of numbers may represent a changing assortment of people. A joke has it that, upon being told that a pedestrian is hit by a car every 20 minutes in New York, the listener responded, "He must get awfully tired of that!" Exactly the same reasoning - or lack of reasoning - appears in statistics that are intended to be taken seriously." (page 43).