The Pareto principle (also known as the 80-20 rule) states that the 20% of the causes is responsible for the 80% of the resulting effects. This principle was first suggested by the management thinker Joseph M. Juran and named it after the Italian economist Vilfredo Pareto, who observed in 1906 that 80% of the land in Italy was owned by 20% of the population. It is a principle with broad application in business; e.g., "80% of your sales come from 20% of your clients."
ICAP published the 2008 consolidated financial statements of the 200 leading Greek groups. Y2008 Top 200 Greek Groups.xps
I found interesting to see if Pereto principle applies.
The earnings of the samples (200 groups, EBITDA basis) reach 19 100 756 K€. The earnings of the first 40 groups (20%) add up to 15 731 590 K€ e.g. the 82% of the total earnings. So Pereto principle applies very accurately to this case.
If we examine the total revenue we'll see that the total revenue of the first 40 groups, in the amount of 98 987 688 K€, represents the 73% of the total revenue of the sample, still statistically acceptable validation of the principle. This percentage also indicates that the big groups have a better gross margin (82% of EBIDTA for 73% of revenue).
We find exactly the same distribution, 82% for EBITDA and 73% for revenue, when we examine the Y2007 financial statements.