<P> Mathematically, the 80 / 20 rule is roughly followed by a power law distribution (also known as a Pareto distribution) for a particular set of parameters, and many natural phenomena have been shown empirically to exhibit such a distribution . </P> <P> The Pareto principle is only tangentially related to Pareto efficiency . Pareto developed both concepts in the context of the distribution of income and wealth among the population . </P> <P> The original observation was in connection with population and wealth . Pareto noticed that 80% of Italy's land was owned by 20% of the population . He then carried out surveys on a variety of other countries and found to his surprise that a similar distribution applied . </P> <P> A chart that gave the inequality a very visible and comprehensible form, the so - called' champagne glass' effect, was contained in the 1992 United Nations Development Program Report, which showed that distribution of global income is very uneven, with the richest 20% of the world's population controlling 82.7% of the world's income . </P>

80 of the effects come from 20 of the causes