Challenges to traditional economic assumptions

Behavioural economics combines insights from psychology and economics to study how people actually make decisions, often challenging the core ideas of traditional economic theory.

Key assumptions in traditional economics

• Utility maximisation - Economic agents, such as consumers or firms, always aim to achieve the highest possible satisfaction or benefit from their choices.
• Rationality - Agents make logical decisions based on complete information to maximise their outcomes.

How behavioural economics improves traditional theory

Behavioural economists argue that these assumptions are unrealistic because they ignore social, psychological, and emotional influences on decisions. Instead of discarding traditional theory, they refine it to better predict real-world behaviour.

Rationality and information in decision-making

Traditional economics portrays individuals as fully rational beings who carefully weigh options to maximise benefits. However, real-life constraints often prevent this ideal behaviour.

Rational individuals

A rational individual, sometimes called 'homo economicus', compares the costs and benefits of different options and selects the one that provides the greatest net benefit. This assumes access to perfect or symmetric information, where all parties in a transaction have the same level of knowledge.

Issues with information and rationality

In reality, people often face imperfect information, leading to poor decisions and market failures. Asymmetric information occurs when one side of a transaction knows more than the other, such as sellers having better details about product quality than buyers. Behavioural economists highlight that rationality alone does not accurately forecast how consumers behave due to these information gaps.

Limits on rational behaviour and biases

People's decision-making is often constrained by practical limitations and mental shortcuts, leading them to make choices that deviate from pure rationality.

Factors limiting rational decisions

• Bounded rationality - Decision-making is restricted by limited time, incomplete or inaccurate information, difficulties in processing data, and computation weakness (struggles with calculating costs and benefits). As a result, individuals often 'satisfice' by choosing a good-enough option rather than searching endlessly for the best one.
• Bounded self-control - Even when people know what maximises their long-term utility, they may lack the willpower to follow through, such as failing to stick to a healthy diet despite its benefits.

Common biases influencing economic choices

• Rules of thumb - Quick decision-making aids, such as always picking a mid-priced item from a list of options.
• Anchoring - Over-relying on an initial piece of information, like letting a first salary offer shape expectations of fair pay.
• Availability bias - Basing probability judgements on how easily examples come to mind, such as overestimating flood risks right after experiencing one.
• Social norms - Conforming to the behaviours of a group, for example, adopting eco-friendly habits if peers prioritise environmental care.
• Habitual behaviour - Repeating actions out of routine, even when better alternatives exist.

The role of fairness in economic choices

Traditional economics assumes people act purely to maximise personal gain, but behavioural insights show that considerations of equity often guide decisions.

Fairness beyond self-interest

Individuals and firms may prioritise altruism and fairness over strict self-interest. For instance, people might donate to charity not just for personal satisfaction, but because it feels right. Similarly, businesses could offer extra employee perks, like enhanced benefits, simply because they view it as fair treatment, rather than for direct utility gains.

Government applications of behavioural economics in policy

Governments use behavioural economics to shape policies that encourage better choices without restricting freedom, often through subtle adjustments to how options are presented.

Choice architecture techniques

Choice architecture involves designing the way decisions are framed to influence outcomes.

Key techniques include:

• Default options - Setting a pre-selected choice that people are likely to stick with, such as automatically enrolling workers in pension schemes to boost savings rates.
• Framing - Presenting information in a way that affects perception, for example, highlighting a treatment's 90% success rate rather than its 10% failure rate to encourage uptake.
• Nudges - Gentle prompts that make desired behaviours easier, like positioning healthier foods prominently in canteens to promote better eating.
• Restricted choice - Limiting available options to simplify decisions, such as offering only a few pension investment plans to avoid overwhelming participants.
• Mandated choices - Requiring a decision to be made, for instance, asking people to specify organ donor status during ID renewals to increase participation.