Hill+Knowlton Strategies held a roundtable event on plastic packaging waste earlier this month, exploring how legislation, taxation and pledges by organisations are drivers of change in the fight against plastic waste. This got our team thinking. These are all critical factors, but where do consumers come in. What’s their role? So we’ve summarised the latest in consumer ‘nudging’, and the creation of sustainable habits where it comes to plastic packaging.

Plastic pollution is one of the prominent environmental issues of our time. Photos of tangled sea life and new studies of microplastics in our food chain provide daily reminders of the scale of this crisis. But is it up to the you, the consumer, to fix it? Or should private industry and the government be stepping up to the challenge?

Enter the plastic bag tax of 2015, which slapped a 5p price tag on a previously free product. Plastic bag consumption has since fallen by an impressive 83%.

But is there a dark side to incentivising environmental behaviour? Shouldn’t we be motivated by the knowledge that it’s inherently the right thing to do?

Well the evidence suggests not. This is why McDonalds is banning plastic straws and Pret a Manger rewards us for bringing our own reusable cups. The observation that our behaviour often fails to match our values is known in behavioural science as the intention-action gap.

Incentives are effective at nudging us back on track, but there are some important caveats that are worth exploring.

The Warm Glow

Behavioural science research suggests that financial incentives can actually reduce our internal motivation to perform a positive behaviour. This is because a financial reward reduces the signal that one is performing a good deed both to oneself and to others.

A huge amount of human behaviour is actually motivated by our desire to demonstrate that we are good people.

Behaviour that is motivated by incentives, rather than being internally motivated, is less likely to lead to long term behaviour change. It’s also less likely to result in people forming pro-environmental attitudes which spillover to other behaviours like recycling and saving energy.

So, in order to sustain the 83% reduction in plastic bag usage, we need to find ways to remind consumers that they are performing a good deed, in addition to saving money.

Moral Licensing

Putting a price on a positive behaviour provides one with the moral license to not perform that behaviour when it is convenient.

As you sneak your groceries into that polyethylene bag, imagine the 5p as a pay-off to the moral policeman in your head, who politely forgets to remind you of your environmental principles.

The perverse effect of moral licensing was demonstrated in an Israeli study which found that parents collected their children late from daycare more frequently after a financial penalty was introduced. The financial penalty acted as less of a deterrent than the social guilt experienced without a fine.

So beware the moral licensing effect. A good rule to remember is charge enough – or don’t charge at all.


Another explanation for the effectiveness of the plastic bag tax is that it acts as a habit-disruptor.

You may have the impression that you are a scrupulous shopper who weighs up the costs and benefits of each product at the supermarket. However, research suggests that shopping behaviour is highly habitual and automatic.

The plastic bag tax acts as a habit-disruptor where the rational brain is woken up to reconsider whether this previously free item is now worth the 5p price tag. This creates a window of opportunity where new improved habits can be formed. For example, if you have recently moved house this is an opportune moment to implement new habits as many of your routines will have naturally been broken.

Disruptive moments should be capitalised on to introduce and reinforce more positive behaviour patterns. For example, consumers will be more receptive to information about the relative carbon footprint of plastic bag alternatives during one of these windows of change. If they adopt a low carbon alternative into a new habit, environmental gains will be maximised.

Top Tips to Reduce Plastic Consumption

This article is not arguing for a reversal of the plastic bag tax or denying the effectiveness of incentives in general. There is a strong argument to be made for a general plastic tax which incorporates the environmental cost of all products containing plastic. The proceeds of such a tax could be used to fund cleaning up our oceans or research into alternative packaging.

However, to embed lasting behaviour change we should augment financial incentives with social marketing or behavioural interventions that increase the internal motivation to perform good deeds. So if you are planning an incentivisation campaign, remember these top tips:

1)    A huge amount of human behaviour is actually motivated by our desire to demonstrate that we are good people.
2)    Beware the moral licensing effect. A good rule to remember is charge enough – or don’t charge at all.
3)    Habit formation is important for lasting behaviour change, remember that even good habits can be hard to break.
Authored By: Saul Wodak