Keeping the streets clean is a joint effort of citizens and city workers. Citizens contribute by not dumping waste and by picking up a broom now and then. However, in large municipalities in the Netherlands, keeping the streets clean has become primarily the task of the municipality. And it is often a massive task. The question is whether this is a sensible policy, as cleaning up by city workers may take away the incentive on the part of citizens to make a contribution – by cleaning up themselves and by refraining from dumping.
Standard economics vs behavioural economics
It is possible to approach this issue from both a standard economic and a behavioural economic perspective. Standard economic theory predicts that individual citizens may be willing to contribute to keeping the streets clean, but when seen from the perspective of common interest, this contribution falls short of the mark. The reason is that individual citizens do not fully take into account the positive effects of their contribution on other citizens. When the municipality starts keeping the streets clean, standard economic theory predicts that citizens take a step back, because there is less point or necessity for them to take care of this themselves. Insights from psychology and behavioural economics, however, point in the opposite direction. Litterers can set a bad example for others to follow. Dirty streets send the message that this is apparently socially acceptable and that it is tolerated by the authorities. That is why waste attracts more waste. The chosen perspective is crucial for providing an answer to the policy issue. Whereas the standard economic perspective warns against too much government involvement, the behavioural economic perspective actually recommends great government involvement.
'The results show that after reducing the frequency of cleaning, there was a sharp rise in the amount of waste dumped by residents'
The best approach
Which approach works best in practice? Together with Ben Vollaard (Tilburg University), I have set up a field experiment to look into this in collaboration with the city of Rotterdam. In one part of a neighborhood in Rotterdam, the frequency of cleaning carried out by the municipality was drastically reduced to two times per week, whereas in the other part the frequency remained once per day. This was maintained for three months. A detailed record of the amount of waste that was encountered on the streets in both areas, both before and during the experiment, makes it possible to reliably estimate what effect the lower frequency of cleaning has on the behavior of the residents. The results show that after reducing the frequency of cleaning, there was a sharp rise in the amount of waste dumped by residents. A second finding is that the increase in the amount of waste dumped by residents remained about the same during the entire three-month period of the experiment. That is, the ‘spontaneous’ response of the people is almost identical to the longer-term response. It appears that the behavioural economic perspective is dominant, both in the short term and in the long term.
Waste attracts waste
In short: waste attracts waste, which is why the returns to cleaning regularly are high. On the other hand, it was also found that when the municipality cleaned up less, more residents made appointments for removing their bulky waste. It would appear that for some people this legal alternative to street dumping is more attractive once they learn that the municipality will not turn up every day to remove waste from the street. Further research is required to see whether the results also apply to other neighborhoods and cities.
This article is based on ‘The Power of a Bad Example: A Field Experiment in Household Garbage Disposal’ by Robert Dur and Ben Vollaard, published in Environment and Behavior. An early exposition in Dutch can be found in ESB, titled ‘Slecht voorbeeld doet slecht volgen in de buitenruimte’.