Behavioural Economics: Why People Don’t Do What the Numbers Say They Should

Behavioural economics sits in the gap between logic and action. Prices, incentives, and data point one way; people often choose another. The difference is not random. It follows patterns—biases, habits, and shortcuts that shape decisions in predictable ways.

Defaults drive behaviour more than choice. Automatic enrolment into pensions in the United Kingdom increased participation not by changing benefits, but by changing the starting position. People stay with the default. Opting out requires effort; most don’t take it. The same pattern appears in subscription renewals and insurance add-ons.

Framing changes outcomes. A product described as “90% fat-free” sells better than one labelled “10% fat.” The numbers are identical. The presentation shifts perception. Retailers use this in pricing—£9.99 feels meaningfully lower than £10, even though the difference is negligible.

Losses carry more weight than gains. A trader in New York City may hold onto a losing position longer than logic suggests, avoiding the feeling of loss. The same bias shows up in everyday decisions—people keep unused subscriptions or underperforming investments to avoid admitting a mistake.

Anchors set expectations. The first number seen becomes a reference point. A property listed at a high initial price in London makes a later reduction feel like value, even if the final price remains high. Restaurants use the same tactic with premium items at the top of menus.

Social proof shapes choice. Crowds signal value. A busy restaurant in Barcelona attracts more customers simply because others are already there. Online reviews amplify this—ratings and comments guide decisions before direct experience.

Present bias shifts timing. Immediate rewards outweigh future benefits. Saving for retirement competes with spending today. Dieting competes with immediate food choices. The long-term outcome loses to short-term satisfaction unless structure intervenes.

Scarcity increases urgency. Limited-time offers and low-stock alerts push decisions forward. A countdown timer on a booking site changes behaviour, even when availability is not genuinely constrained. The perception of scarcity is enough.

Habits override analysis. Repeated actions become automatic. A commuter buying coffee daily in London does not re-evaluate the decision each time. Behaviour becomes routine, independent of price or value.

Behavioural economics connects psychology, pricing, and decision-making. It explains why outcomes differ from what pure logic predicts.

People do not act as perfectly rational agents. They act as humans—consistent in their inconsistencies.