Pareto was an Italian economist and sociologist back at the turn of the last century and is most famous for the development of a technique to identify the basic drivers of a situation, i.e. among the many potential causes, which few causes result in most of the outcomes. Very frequently this follows an eighty:twenty rule, e.g. 20% of drivers cause 80% of the accidents.
I have recently finished reading the NEA's 2004 report Reading at Risk. They have the data to answer a number of questions but it is not presented in a fashion that makes it easy to check their figures or do your own analysis.
One of the questions I had was to what degreee is reading a demographically concentrated activity in America. While they do not answer that in the report, there is a way to back into an answer through manipualtion of some of the data they do present along with a couple of conservative assumptions.
The result is that you can determine that 83% of all literature read in the US is read by 16% of the population.
Not surprising I guess, but arresting. It implies a high concentration of "cultural literacy" and capacity for close reading among a small part of the population. Instinctively, I can't help but feel that that is not too good.