Report urges caution over recycling reward schemes
Questions have been raised about the benefit of rewards for residents who recycle.
Reward schemes work well at first but it is unclear whether they lead to long-term changes in behaviour, a London Assembly report said.
Darren Johnson, deputy chairman of the environment committee, warned against a "one-size-fits-all" approach.
The report comes after Lambeth residents became the first in London to be offered recycling rewards.
The Carrots and Sticks report released by the assembly's environment committee on Tuesday says London has the lowest recycling rate in the country, with a only third of waste being recycled.
The report says recycling rates have improved "dramatically" where boroughs have penalty and reward schemes.
But it warns there are drawbacks.
It outlines concerns that London's large number of flats, transient population and the number of households without internet access, could affect the success of reward schemes.
Compulsory schemes could discourage ongoing communication with residents, it warns.
The committee heard from those running reward schemes that participants may need to be given fresh incentives once recycling rates reach a plateau.
Mr Johnson said: "It is very encouraging that rates have improved so considerably in recent years, but there is much more to be done to cut down on London's waste mountain.
"The capital does face unique challenges and it is clear that there isn't a one-size-fits-all approach.
"Whatever method boroughs use to reduce waste must result in long-term changes if we are to avoid the unwanted economic and environmental consequences of sending tonnes of rubbish to landfill every year."
The committee called for any schemes to be designed to address London-specific issues around housing stock, transient populations and equality of access.
It warned weight-based schemes could lead to individuals deliberately generating more waste to maximise their chance of a reward.
It also said more evidence was needed that incentive schemes worked and communication about the value of recycling was key to a scheme's success.
Julian Kirby, resource use campaigner for Friends of the Earth, said: "The evidence is quite clear that for behaviour change to be sustainable it has to come from inside and from a sense of people's own values.
"The problem with using incentives is you externalise the motivation for behaviour change and that means that when you take that incentive away people are liable to stop the behaviour change you are trying to reinforce."
He said councils instead needed to "reduce the complexity" of recycling and collect more recyclable waste more frequently.
"Councils need to reduce the frequency of black bag waste collections so long as they increase the frequency of recycling collections and collect food waste every week," he added.
"What is crucial is that people understand that recycling does save councils a lot of money, which does saves the tax-payer a lot of money."