Welcome to Behavioural Economics!
In your previous lessons, you might have learned that consumers are perfectly rational beings who always make the "perfect" choice to get the most satisfaction. But let’s be honest—have you ever bought a snack you didn't need just because it was at the eye level in a shop? Or bought a pair of shoes just because your friends had them?
In this chapter, we explore Behavioural Economics. This is the study of why humans don't always act like robots and how social, emotional, and cognitive factors influence our decisions. Don’t worry if this seems a bit different from the graphs you’ve seen so far; it’s all about understanding human nature!
1. The Traditional View: "Homo Economicus"
Traditional economic theory is built on the assumption of Rational Decision Making. This theory assumes that:
• Consumers want to maximize utility (satisfaction).
• They have perfect information about all choices.
• They have the mathematical brainpower to calculate which choice is best.
• They act purely out of self-interest.
The Reality Check:
Think of this "traditional consumer" as a calculator with legs. In the real world, we are often tired, rushed, or influenced by our feelings. This is where behavioural economics comes in!
Quick Review: Traditional theory assumes we are utility maximizers with perfect logic. Behavioural economics argues we are often "predictably irrational."
2. Why We Aren't Perfectly Rational
The syllabus (Section 3.1.2.1) highlights that our decisions are influenced by social and emotional factors. Economists call the limits to our logic Bounded Rationality.
A. Bounded Rationality
Humans cannot be perfectly rational because:
1. Limited Time: We often have to make decisions quickly (e.g., choosing a sandwich during a 5-minute break).
2. Limited Information: We rarely know every single detail about every product available.
3. Limited Computational Ability: Our brains aren't powerful enough to calculate the exact utility of every possible purchase.
B. Bounded Self-Control
Even when we know what is "best" for us (like saving money or eating healthy), we often lack the willpower to do it.
Example: You know saving $10 today is better for your future, but the emotional "want" for a coffee right now is stronger.
Memory Aid: The "Three Ls"
\nTo remember why we aren't perfectly rational, think of Limited Time, Limited Info, and Limited Brainpower.
\n\n
3. Cognitive Biases (Mental Shortcuts)
\nBecause our brains are busy, we use Heuristics (rules of thumb) to make decisions faster. While helpful, these "shortcuts" often lead to Cognitive Biases—systematic errors in our thinking.
\n\nAnchoring
\nThis happens when we rely too heavily on the first piece of information we see (the "anchor").
\nExample: A shop shows a shirt originally priced at $100, now "on sale" for $40. The $100 is the anchor. Even if the shirt is only worth $20, $40 feels like a bargain because you compared it to the first number you saw.
Availability Bias
We judge the likelihood of something based on how easily we can remember examples of it.
Example: People might be afraid of flying because they saw a plane crash on the news recently, even though statistically, driving a car is much more dangerous. They choose the "safer" looking option based on what's fresh in their mind.
Social Norms (Social Factors)
As mentioned in syllabus section 3.1.1.5, our decisions are influenced by the moral and political judgements of society. We often do things simply because "everyone else is doing it."
Example: You might start recycling not because you calculated the utility, but because your neighbours do, and you want to fit into the social norm.
Key Takeaway: Biases like anchoring and social norms mean our demand for goods isn't just about price; it’s about how the choice is presented to us.
4. Choice Architecture and Government Intervention
Since humans make "mistakes" in their choices, the Government (Section 3.1.5.7) or businesses can use Choice Architecture to influence us. This is how choices are designed and presented.
Nudges
A Nudge is a small change in the environment that encourages people to make a specific choice without banning any options or changing prices significantly.
Example: Placing fruit at eye level in a school cafeteria while putting chocolate on the bottom shelf. You can still buy chocolate, but you are "nudged" toward the healthier choice.
Framing
The way a choice is worded can change your decision.
Example: A doctor says a surgery has a "90% success rate." You feel positive. If they say it has a "10% failure rate," you might feel scared and refuse, even though the math is exactly the same!
Default Choice
People tend to stick with the "automatic" option because it requires no effort.
Example: In some countries, you are automatically enrolled in a pension savings plan unless you "opt-out." Because humans are lazy (bounded rationality!), most stay in the plan, leading to higher savings for the country.
5. Summary and Common Mistakes
Quick Review Box:
• Rationality: The (often wrong) idea that we always choose the best option.
• Bounded Rationality: We have limits on time, info, and brainpower.
• Heuristics: Mental shortcuts (Rules of Thumb).
• Anchoring: Being stuck on the first number we see.
• Nudge: Gently pushing someone toward a "better" choice without force.
Common Mistakes to Avoid:
• Mistake: Thinking a "Nudge" is the same as a law.
Correction: A law forces you (like a fine for speeding); a nudge encourages you (like a sign showing your speed to make you feel guilty).
• Mistake: Assuming behavioural economics says people are "stupid."
Correction: It just says we are human and our brains use shortcuts to save energy.
Final Thought: Understanding these influences helps economists design better policies. Instead of just taxing "bad" things (like sugar), they can use choice architecture to help us make better decisions for ourselves!