Magazine article American Libraries

Exceptional Institutions: Libraries and the Pareto Principle

Magazine article American Libraries

Exceptional Institutions: Libraries and the Pareto Principle

Article excerpt


The best public libraries are exceptional institutions--where "exceptional" is a literal description, not an encomium. Good public libraries cater to exceptions: to the ideas, people, and literature too often ignored in a majoritarian society. The best public libraries are also "counter-Pareto" institutions: They go beyond the Pareto Principle for the long term good of the community.

What's the Pareto Principle? You've almost certainly used the observation even if you don't recall the name. Think of it as the 20:80 (or 80:20) rule. Twenty percent of the contributors in a field account for 80% of the field. So, for example, 20% of a restaurant's menu probably generates 80% of its business; 20% of a store's customers produce 80% of its business; 20% of currently released movies will do 80% of the box office business; 20% of advertising produces 80% of results. On the flip side, 20% of customers will generate 80% of the complaints--and solving 20% of the problems in a process may resolve 80% of the failures. The Pareto Principle holds true in an astonishingly wide variety of fields, including many aspects of librarianship.

Who was Pareto? Vilfredo Pareto (1848--1923) was an economist, sociological theorist, and--supposedly--avid gardener. Born in Paris, he graduated from the University of Turin and was a professor of political economy at the University of Lausanne in Switzerland. Pareto observed that 20% of the population of Italy owned 80% of the land. It's also said that he later observed that 20% of the peapods in his garden yielded 80% of the peas.

Did Vilfredo Pareto formulate a principle stating that in most fields a few of the contributors (20%) account for the bulk of the effect (80%)? Probably not. According toJ. M. Juran, known as the "Dean of American consultants on quality control," the first published use of the term "Pareto Principle" was in the paper "Universals in Management Planning and Controlling," published in the October 1954 Management Review. Juran generalized Pareto's observations to other fields and chose to use Pareto's name for that generalization.

Juran's belated confession that the Pareto principle should probably be the Juran principle comes in a charming article, "The Non-Pareto Principle: Mea Culpa" ( However, as he notes, it's far too late to rename the principle of unequal distribution.

Pareto offered an observation in one field-one that echoed and qualified similar observations from previous scholars. Juran generalized the observation into a principle that seems to hold across most endeavors. That's all to the good: The Pareto Principle (whether rightly named or not) is useful shorthand for the sort of distribution that seems prevalent in many fields.

Juran went one step further, a step that made sense for quality control but causes problems elsewhere. He characterized the Pareto Principle as separating the "vital few" from the "trivial many." When you're locating the 20% of problems in a system that cause 80% of the difficulties in using that system, the distinction makes sense--particularly because you can proceed in an iterative fashion. That is, once you've corrected the worst 20%, chances are that 20% of the remaining problems--16% of the original--are causing 80% of the remaining difficulties--again, 16% of the original. Solve those (36% of the original problems) and you've approached perfection (eliminating 96% of the original difficulties).

When the Pareto Principle becomes the basis for decision-making, "trivial" can be a tricky word, as it slides quickly over into "irrelevant." You see that at some banks, stock brokerages, and other service institutions, where nearly all customer service is aimed at the 20% of depositors who represent 80% of the deposits: the rest of us are trivial. Some stores seem intent on reducing their customer base to the "vital" 20%; from a purely profit-oriented perspective, that may be a reasonable attitude. …

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