襄城区离樊城区远吗:What is the Pareto Principal?

http://en.wikipedia.org/wiki/Pareto_principle

The pareto principle (AKA 80:20 Rule)

The so-called Pareto principle (also known as the 80-20 rule, the law of the vital few and the principle of factor sparsity) states that for many phenomena 80% of consequences stem from 20% of the causes. The idea has rule-of-thumb application in many places, but it is commonly misused.

The principle was suggested by management thinker Joseph M. Juran. It was named after the Italian economist Vilfredo Pareto, who observed that 80% of property in Italy was owned by 20% of the Italian population. (Since J. M. Juran adopted the idea, it might better be called "Juran's assumption".) The assumption is that most of the results in any situation are determined by a small number of causes. This idea is often applied to data such as sales figures: "20% of clients are responsible for 80% of sales volume." Such a statement is testable, is likely to be approximately correct, and may be helpful in decision making.

The principle is often misconstrued because of the coincidence that 80 + 20 = 100: it could just as well read that 80% of the consequences stem from 10% of the causes. Many people would reject such an "80-10" rule, but it is mathematically meaningful nevertheless.

The principle can be viewed as recursive, and may be applied not only to the top 20% of causes; thus there would be a "64-4" rule (64% of the consequences stem from 4% of the causes), and a "51.2-0.8" rule, and so on.

In the opposite direction, Tipton Cole has observed that the Pareto Principle applies to the residue of its first application, yielding a "96-36" rule.

Certain common applications of the principle misunderstand the original intent and are not, by themselves, credible. For instance: "20% of individuals in an organization perform 80% of the work." Or: "20% of our advertising creates 80% of our increased sales."

This is a special case of the wider phenomenon of Pareto distributions.

The Pareto principle is unrelated to Pareto efficiency, which really was introduced by Vilfredo Pareto.

帕累托原则
是经济学上的一个专业术语

什么是Pareto原则？

1879年，意大利人Villefredo Pareto提出：社会财富的80%是掌握在20%的人手中，而余下的80%的人只占有20%的财富。渐渐地，这种“关键的少数（vital few）和次要的多数（trivial many）”的理论，被广为应用在社会学和经济学中，并被成之为Pareto原则（Pareto Principle）。