The idea that a few root problems are responsible for the large majority of consequences. The Pareto principle is derived from the work of Vilfredo Pareto, a turn-of-the-century Italian economist who studied the distributions of wealth in different countries. He concluded that a fairly consistent minority about 20% of people controlled the large majority about 80% of a society's wealth. This same distribution has been observed in other areas and has been termed the Pareto principle. It is defined by J.M. Juran as the idea that 80% of all effects are produced by only 20% of the possible causes