Our Science


The classic theory behind criminal decision making is called 'expected utility theory'. What it says basically is that thieves make rational decisions about what and when to steal.

The main thing that would put them off would be the prospect of being caught and punished.

This theory has driven everything from sentencing policy to the adoption of crime prevention strategies such as the invisible marking of goods using ultraviolet markers.

The only slight problem is that it doesn't work, never has, never will, just like invisible property marking, more on that later.

During the most severe economic recession since the 1930s crime has actually decreased overall rather than rising.

This goes completely against the theory of the rational criminal who would be expected to have become more numerous, more determined and more violent as economic conditions declined.

However the recent emergence of a new field of science, behavioural economics, has allowed a better understanding of how criminals make the decision whether or not to steal.

Behavioural Economics

Behavioural economics, pioneered by Professor Daniel Kahneman and Amos Tversky said that people were not always rational in their decision making under uncertainty.

There were evolutionary thinking biases that fundamentally affected that process. They developed an approach known as Prospect Theory.

This was explained by Nobel prize winner Kahneman and Tversky in their 1979 paper Prospect Theory: An Analysis of Decision under Risk.

It says that people make decisions factoring in the potential value of loss or gains and that the assessment of risk is not simply based on the certainty of punishment.

Instead it is based on their emotional reaction to the prospect of gain in comparison to potential losses of things like liberty or cash but also loss of status or shame within their peer group.

This brings economic theory back in line with the thinking of the founder of modern economics Adam Smith.

His book The Theory of Moral Sentiments talked about concepts such as fairness and justice motivating people rather than simple economic considerations.