Bounded rationality is the idea that people try to make rational decisions, but their rationality is limited by three main constraints:

1. Limited information – We rarely know everything relevant.
2. Limited cognitive capacity – Our brains can't analyze every possibility.
3. Limited time – We often have to decide before we have all the answers.

The concept was introduced by Herbert A. Simon, who argued that real human decision-making is very different from the "perfectly rational" decision-makers assumed in many economic models.

An example

Imagine you're buying a laptop.

A perfectly rational person would:

• Find every laptop available worldwide.
• Compare every specification, review, price, warranty, and future resale value.
• Calculate which one maximizes their satisfaction.

In reality, you might:

• Read a handful of reviews.
• Set a budget.
• Pick the first laptop that seems good enough.

That "good enough" choice is called satisficing—another concept introduced by Simon. Instead of finding the absolute best option, people often stop searching once they find one that meets their needs.

Why bounded rationality happens

Our brains face practical limits:

• Memory is finite.
• Attention is limited.
• Complex calculations are mentally expensive.
• The world is uncertain.

So people use heuristics (mental shortcuts), such as:

• Buying a familiar brand.
• Following a trusted friend's recommendation.
• Choosing the middle-priced option.

These shortcuts often work well, although they can sometimes lead to systematic biases.

Bounded rationality vs. perfect rationality

Perfect rationality	Bounded rationality
Knows all relevant information	Has incomplete information
Can process unlimited complexity	Has limited mental resources
Finds the optimal choice	Finds a satisfactory choice
Common in economic theory	Describes how people actually decide

Where it matters

Bounded rationality helps explain behavior in many fields:

• Economics: Why consumers don't always maximize utility.
• Business: Why managers use rules of thumb instead of exhaustive analysis.
• Politics: Why policymakers make decisions with incomplete evidence.
• Artificial intelligence: Why algorithms often use approximations instead of searching every possible solution.
• Everyday life: Choosing careers, homes, investments, or relationships without perfect knowledge.

A simple analogy

Think of trying to find the highest hill in a dense fog.

A perfectly rational person somehow has a map of every hill and walks to the tallest one.

A boundedly rational person can only see a few meters ahead, so they keep climbing until they reach a hill that's high enough and stop. It may not be the tallest hill, but it's a reasonable solution given the limits they face.

In short, bounded rationality doesn't mean people are irrational. It means people are as rational as they can be given limited information, limited cognitive resources, and limited time.