- Define and explain Rational Choice Theory in your own words
- Use key terms such as bounded rationality accurately
- Apply what you have learned to new examples and questions
- Avoid the common mistakes learners make with this topic
Traditional economics assumes rational decision-makers, but real people are predictably irrational. Behavioural economics blends psychology with economics to explain why we make the choices we do — and how small 'nudges' can improve them.
This lesson focuses on Rational Choice Theory: examine the traditional model of the rational consumer.
Examine the traditional model of the rational consumer.
Key ideas
From homo economicus to real humans
Neoclassical theory models people as rational utility-maximisers with stable preferences. Behavioural economists show decisions are shaped by framing, emotions and social norms: the same product described as '90% fat-free' versus '10% fat' gets very different responses.
Nudges in action
Because biases are predictable, choice architecture can help: auto-enrolling workers into pensions (with opt-out) hugely raised UK saving; smaller plates reduce food waste; default green-energy tariffs increase uptake. Libertarian paternalism argues such nudges preserve freedom while improving welfare — critics warn of manipulation.
Key term — bounded rationality: Herbert Simon's idea that rationality is limited by information, time and mental capacity, so people 'satisfice' (settle for good enough) rather than optimise.
What is bounded rationality?
The idea that people's rationality is limited by information, time and mental capacity, so they satisfice rather than optimise.
Answer: The idea that people's rationality is limited by information, time and mental capacity, so they satisfice rather than optimise.
- Calling every error 'irrational' Behavioural biases are systematic and predictable — that is precisely why they can be modelled and nudged, unlike random errors.
- Thinking nudges remove freedom A true nudge preserves choice — banning an option is a mandate, not a nudge.
Practice
Framing — the same information presented positively changes choices.
Any one of: it can be manipulative; it may not address root causes; effects may not transfer across contexts.
Losses hurt roughly twice as much as equivalent gains please, so people avoid risks involving losses.
Inertia/status-quo bias: most workers stick with the default of being enrolled rather than opting out.
Quick check
Which of these best defines "bounded rationality"?
What is present bias, and how does it affect saving?
- Rational Choice Theory: examine the traditional model of the rational consumer.
- From homo economicus to real humans: Neoclassical theory models people as rational utility-maximisers with stable preferences.
- loss aversion: The finding from Kahneman and Tversky's prospect theory that losses hurt roughly twice as much as equivalent gains please, making people avoid risks involving losses.
- Watch out for: calling every error 'irrational'