Look at these two graphs. Rare catastrophic events are the long tails and that makes sense. But why is Bill Gate's wealth the head on the graph on the right? Shouldn't it be the tail as well? Taking a close look, the graph on the right is not the PDF, but rather just a list of people sorted by wealth, right? Then why do they call THIS Pareto? If the head and the tail are reversed? I know you can still argue that it does illustrate the 80/20 principle, but I am still confused about the head/tail terminology. What do you call the graph on the right?