There is a principle known as the Pareto principle - or more loosely, the 80/20 principle.
The 80/20 principle is used to describe the relationship between a myriad of things. For example effort versus impact. It is typically found that the first 20% of effort is responsible for 80% of the impact. It might also describe the relationship between sales people and sales - 20% of sales people are likely to be responsible for 80% of sales. It is amazingly reliable and good consultants and managers use it as a "gut feel" measure to make decisions about a myriad of different actions. More than this, successful people often intuitively apply it to managing their lives.
So, it is likely that 20% of criminals perpetrate 80% of crime. Various anecdotal and researched evidence of this exists and my reading of books like "The Tipping Point," "Freakonomics" and discussions with police personnel seem to bare this out.
So those of us in the Sandton area of Johannesburg have got reason to celebrate then - the Sandton police have arrested the Sandton Knife Gang. This group of five brothers have been linked to 18 different robberies in the Sandton area thus far. Since their arrest, crime has already dropped in the area!
Congratulations SAPS Sandton!
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