Getting people on the buses

Financial incentives aren’t the only way to encourage people to be more environmentally friendly. According to Ellen Matthies and colleagues at the Ruhr-Universitat in Germany, many people do care about the environment, despite their polluting habits, and so an alternative approach is to invite them to commit themselves to a change in behaviour. They tested a two-pronged strategy that involved inviting a voluntary commitment on the one hand, paired with a habit-breaking incentive on the other.

Matthies’ team recruited 297 people who made a regular journey in their car that could easily be completed by bus. Some were given a free bus ticket, while others were given a description of the harm to the environment that cars do, and invited to commit to a choice of green behaviours, including swapping their car for public transport during the next two weeks. Some participants were given the ticket as well as being invited to commit to a change of behaviour. Control participants received no intervention. Telephone interviews before, during and after the interventions were used to monitor people’s travelling behaviour.

In the short-term, the free ticket, the voluntary commitment, or both together, all increased the number of people who tried swapping their car for public transport, with the free ticket being most effective. For example, seven per cent of participants tried the bus before getting a free ticket, compared with 16.3 per cent afterwards. However, at the final 26 week follow up, the researchers found that it was those participants who had both committed themselves voluntarily to trying the bus and received a free ticket, who were most likely to still be using more public transport than at baseline.

The researchers concluded: “From a practical perspective, it follows that not only so-called “hard measures” [i.e. financial incentives] can be applied to alter the problematic behaviour, but that also ‘soft measures’ (e.g. plea for commitment), which target the moral dimension of environmental behaviour, may be helpful under some circumstances: if readiness for a commitment is high and if the plea for commitment is combined with a habit-defrosting strategy”.
Matthies, E., Klockner, C.A. & Preisner, C.L. (2006). Applying a modified moral decision making model to change habitual car use: How can commitment be effective? Applied Psychology, an International Review, 55, 91-106.

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

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