In this kind of situation one might well ask: why continue to make the 80 per cent of products that only generate 20 per cent of profits? Companies rarely ask these questions, perhaps because to answer them would mean very radical action: to stop doing four-fifths of what you are doing is not a trivial change.

There are two routes to achieving this. One is to reallocate the resources from unproductive to productive uses, the secret of all entrepreneurs down the ages. Find a round hole for a round peg, a square hole for a square peg, and a perfect fit for any shape in between. Experience suggests that every resource has its ideal arena, where the resource can be tens or hundreds of times more effective than in most other arenas. The other route to progress—the method of scientists, doctors, preachers, computer systems designers, educationalists and trainers—is to find ways to make the unproductive resources more effective, even in their existing applications; to make the weak resources behave as though they were their more productive cousins; to mimic, if necessary by intricate rote-learning procedures, the highly productive resources. The few things that work fantastically well should be identified, cultivated, nurtured and multiplied. At the same time, the waste—the majority of things that will always prove to be of low value to man and beast—should be abandoned or severely cut back.

Certainly, the principle brings home what may be evident anyway: that there is a tragic amount of waste everywhere, in the way that nature operates, in business, in society and in our own lives. If the typical pattern is for 80 per cent of results to come from 20 per cent of inputs, it is necessarily typical too that 80 per cent, the great majority, of inputs are having only a marginal—20 per cent—impact.

Both phenomena help to show how the universe abhors balance. In the former case, we see a natural flight away from a 50/50 split of competing phenomena. A 51/49 split is inherently unstable and tends to gravitate towards a 95/5, 99/1 or even 100/0 split. Equality ends in dominance: that is one of the messages of chaos theory. The 80/20 Principle’s message is different yet complementary It tells us that, at any one point, a majority of any phenomenon will be explained or caused by a minority of the actors participating in the phenomenon. 80 per cent of the results come from 20 per cent of the causes. A few things are important; most are not.

Related to the idea of feedback loops is the concept of the tipping point. Up to a certain point, a new force—whether it is a new product, a disease, a new rock group or a new social habit such as jogging or roller-blading—finds it difficult to make headway. A great deal of effort generates little by way of results. At this point many pioneers give up. But if the new force persists and can cross a certain invisible line, a small amount of additional effort can reap huge returns. This invisible line is the tipping point.

We can see positive feedback loops operating in many areas, explaining how it is that we typically end up with 80/20 rather than 50/50 relationships between populations. For example, the rich get richer, not just (or mainly) because of superior abilities, but because riches beget riches. A similar phenomenon exists with goldfish in a pond. Even if you start with goldfish almost exactly the same size, those that are slightly bigger become very much bigger, because, even with only slight initial advantages in stronger propulsion and larger mouths, they are able to capture and gobble up disproportionate amounts of food

At the heart of this progress is a process of substitution. Resources that have weak effects in any particular use are not used, or are used sparingly. Resources that have powerful effects are used as much as possible. Every resource is ideally used where it has the greatest value. Wherever possible, weak resources are developed so that they can mimic the behaviour of the stronger resources.

Why should you care about the 80/20 Principle? Whether you realize it or not, the principle applies to your life, to your social world and to the place where you work. Understanding the 80/20 Principle gives you great insight into what is really happening in the world around you.

The reason that the 80/20 Principle is so valuable is that it is counterintuitive. We tend to expect that all causes will have roughly the same significance. That all customers are equally valuable. That every bit of business, every product and every dollar of sales revenue is as good as another. That all employees in a particular category have roughly equivalent value. That each day or week or year we spend has the same significance. That all our friends have roughly equal value to us. That all enquiries or phone calls should be treated in the same way. That one university is as good as another. That all problems have a large number of causes, so that it is not worth isolating a few key causes. That all opportunities are of roughly equal value, so that we treat them all equally. We tend to assume that 50 per cent of causes or inputs will account for 50 per cent of results or outputs. There seems to be a natural, almost democratic, expectation that causes and results are generally equally balanced. And, of course, sometimes they are. But this ‘50/50 fallacy’ is one of the most inaccurate and harmful, as well as the most deeply rooted, of our mental maps.

The key point is not the percentages, but the fact that the distribution of wealth across the population was predictably unbalanced.

In business, many examples of the 80/20 Principle have been validated. 20 per cent of products usually account for about 80 per cent of dollar sales value; so do 20 per cent of customers. 20 per cent of products or customers usually also account for about 80 per cent of an organization’s profits. In society, 20 per cent of criminals account for 80 per cent of the value of all crime. 20 per cent of motorists cause 80 per cent of accidents. 20 per cent of those who marry comprise 80 per cent of the divorce statistics (those who consistently remarry and redivorce distort the statistics and give a lopsidedly pessimistic impression of the extent of marital fidelity). 20 per cent of children attain 80 per cent of educational qualifications available. In the home, 20 per cent of your carpets are likely to get 80 per cent of the wear. 20 per cent of your clothes will be worn 80 per cent of the time. And if you have an intruder alarm, 80 per cent of the false alarms will be set off by 20 per cent of the possible causes. The internal combustion engine is a great tribute to the 80/20 Principle. 80 per cent of the energy is wasted in combustion and only 20 per cent gets to the wheels; this 20 per cent of the input generates 100 per cent of the output!

The 80/20 Principle asserts that a minority of causes, inputs or effort usually lead to a majority of the results, outputs or rewards. Taken literally, this means that, for example, 80 per cent of what you achieve in your job comes from 20 per cent of the time spent. Thus for all practical purposes, four-fifths of the effort—a dominant part of it—is largely irrelevant. This is contrary to what people normally expect.