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title: The Pareto Principle
modified: 2026-06-10
---

# What is the Pareto Principle?

[The Pareto Principle](https://www.google.com/search?q=The+Pareto+Principle), also known as the 80/20 Rule, Law of the Vital Few, states that roughly 80% of effects come from 20% of causes. It was named after Italian economist [Vilfredo Pareto](https://www.google.com/search?q=Vilfredo+Pareto), who observed that 80% of Italy’s land was owned by 20% of the population.

# Key Ideas

* **Imbalance:** Outcomes are often distributed unevenly. A small number of inputs or activities are responsible for the majority of results.
* **Not always 80/20:** The ratio is not always exactly 80/20, but the principle highlights the general pattern of imbalance.

# Examples

* **Business:** 80% of sales often come from 20% of customers.
* **Productivity:** 20% of tasks may yield 80% of the value.
* **Software:** 80% of errors are caused by 20% of bugs.

# Implications

* **Focus on the vital few:** Identify and prioritize the most impactful activities, customers, or problems.
* **Time management:** Spend more time on high-leverage tasks.
* **Problem-solving:** Address the small number of causes that create the majority of issues.