Consumers follow the crowd...even to the petrol pump

In the last few days, we have been witness to an extraordinary phenomenon: the herd mentality of the British consumer.

We are at least seven days away from any potential industrial action by tanker drivers which could upset the availability of petrol and yet, following government advice to top up our tanks or hoard small supplies, we set off in our droves to forecourts this week demonstrating almost Blitz-like resolve. As a consequence, the independent retailers' group RMI Petrol reported that demand for petrol rose 172% on a single day, while diesel was up 77%. Halford’s similarly reported a staggering 500% rise in sales of jerry cans.

Some have suggested that the panic-buying is a direct result of the government ‘nudging’ people towards specific outcomes. Perhaps, it has been said, the government needed this to happen for political reasons, as a distraction from the economy, the cash for dinner scandal, to back Labour into a corner over union funding or even to generate a short term petrol duty bonanza to offset the prospect of a double dip recession.

But that would be to suggest that the response has been unusual for British consumers. And that’s plainly not true. British consumers have been in thrall to the ‘Delia Effect’ for the last few years. In 2009 her Christmas television series sparked a rush for cinnamon sticks, Marsala wine and other more obscure ingredients for her chestnut cupcakes. Sainsbury's reported sales of cinnamon sticks up 200 per cent on the same time the previous year, while Marsala wine - an ingredient in Delia's panettone trifle - was up 300 per cent. Sales of pickled walnuts, which Delia teamed with braised venison, doubled.

Delia had a similar impact in 2011 when Waitrose boxed up all of the ingredients you needed to make her traditional Christmas cake. The supermarket even suggested that they expected to see neighbours and friends competing over the most creatively decorated cake.

And it’s not only food. Earlier this year Amazon reported sales of telescopes were up 491% in the three hours after the transmission of BBC2's Stargazing Live, presented by Professor Brian Cox.

Whether it is rushing to fill up your car when there is no shortage of petrol, or racing to get the last cinnamon stick for a cup cake recipe, some would say this is irrational consumer behaviour. But then the advent of behavioural economics has shown that, whilst many marketing strategies are based on the notion that consumers make rational purchasing decisions, study after study have shown that this is not the case.

Simply defining your target audience through conventional and established techniques is no longer enough. Now, marketers must understand a potential customer's likely behaviour. Behavioural economics shoots holes in this by demonstrating how our behaviour is, to a large extent, unconscious, irrational and socially driven. However, whilst we may be dealing with the irrational it can also be predictable.

And one of the key findings of behavioural economics is that we are heavily influenced by other people. We tend to observe and copy what others do and, generally, like conforming. When sponsoring someone the amount you give will be heavily influenced by what other people have already put down. So, if everyone else is making Delia’s cake or looking for Brian’s planets, we don’t want to be out of the loop. And with that, I’m off to fill up the car.