The Pareto Principle

The pareto principle, sometimes known as the 80-20 rule, the law of the vital few, or the principle of factor sparsity, states that for many events, roughly 80% of the effects come from about 20% of the causes.

It's a common rule of thumb in business...  80% of the sales come from 20% of your clients, for example.

The principle has its basis in economics.  Italian economist Vilfredo Pareto noticed that 80% of the land in Italy was owned by 20% of the population.  It has also been noted that the richest 20% of the people in the world have about 80% of the world's income.

It seems to have application everywhere.  One might guess that they wear their favorite 20% of their clothing 80% of the time.  Microsoft noted that fixing 20% of the bugs in their software resulted in an 80% reduction in errors and crashes.  My favorite, late director, Syd Riggs, even applied this to stage combat.  The person giving the action was responsible for 20% and the person receiving the action was responsible for 80%, making stage combat much safer.  (Or did she say 90-10?  I wish she were still alive so I could ask her. )

The one that's bugging me today, though, is that, according to my dentist, they perform 80% of their work on 20% of their patients.  And yes, I'm in that wonderful 20%.

Ugh.