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Writer's pictureCris

Pareto's Principle: The 80/20 rule



Pareto's principle states that:

80% of effects come from 20% of causes

The concept applies to many fields. Microsoft (nerd), for instance, noted that 20% of the code contains 80% of the bugs. Also, the big guys there noted that by fixing 20% of the most reported bugs, they would have avoided 80% of all their problems.

We don't need to be big guys to apply the same criteria. I believe that in any of your exams, you could study 20% of the material to answer 80% of the questions, for instance.


Even though the concept doesn't seem to apply to goals and productivity, it definitely does when we change the words effects and causes with results and effort. The rule then becomes:

80% of results come from 20% of the effort
  • 80% of your profit comes from 20% of your clients, as explained by Tim Ferriss in his book, The 4-Hour Workweek.

  • 80% of your work is done in 20% of your time

  • 80% of your research topic is covered in only 20% of all the related papers!:)

The same rule still works as follows:

80% of the hassle comes from 20% of the problems
  • 80% of your stress is caused by 20% of people around you

  • 80% of your unhappiness is caused by 20% of your bad habit

  • 80% of the calories you ingest come from 20% of your diet (junk food)

If we're still on the same page, these numbers should let you think, undoubtedly.


If in 100 hours you would write 10 scientific papers (a piece of cake), and in 20 hours you would write 8 of them, I would definitely go for option B!

Also (follow me), in this second scenario -- the 20-hour one -- you're much more focused than in the scenario where you work for 100 hours.

You might not only work much less and still obtain terrific results, but you might also produce more qualitative work!


In the last weeks, I noticed that in 20% of my time (about 2 hours) of intense work, I could check off about 70% of the items on my to-do list. I've then decided to reserve a fixed time slot (8 a.m. to 10 a.m. every day) for this highly productive session.

I put this slot after a short walk, an espresso, 10 minutes of meditation and before the weightlifting session. It works great because I'm still fasting from the night before (no digestion involved → more focus), there's nobody at home (but my dog), and I'm pretty relaxed.

Moreover, I can enjoy the weightlifting session knowing that once back home, I have only 20-30% of the to-do items left.


Did you know this principle? What's your thought?



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