The Use of Feedback to Promote Food Waste Collections

1. The Use of Feedback to Promote Food Waste Collections Hisako Nomura and Sarah Cotterill Institute for Political and Economic Governance (IPEG)

2. 1. Background • Disposal of biodegradable waste to landfill results in emissions of methane, one of the powerful greenhouse gas (GHG) emissions which contribute to global warming. • a new target to divert food waste from landfill disposal (DEFRA, 2007) • the actions of citizens are essential to implement policies for a better environment, largely through modifying their individual behaviors (Jackson 2005).

3. Individual feedback Group feedback Information Plea only Control Schultz (1998) 2. Feedback based recycling campaign 50% 38% Baseline intervention Post-intervention Observation Period

4. The use of smiley face and frown face • Schultz et. al. found that putting both a smiley face for low energy use and sad face for high energy use on the power bill encouraged consumers to use less energy. Schultz et. al. (2007) also in Thaler and Sunstein (2008)

5. Feedback as “nudge” • ‘Nudge’ involves creating the context in which people make choices to encourage certain responses (Thaler and Sunstein, 2008). • Timely feedback is an effective way to create the context where people may be encouraged to act on, and to achieve benefits for themselves and for their social network • Further discussions on ‘nudge’ and ‘think’ as Government’s strategy to shift civic behaviour (John, Smith, and Stoker, 2009)

6. Behavioural Psychology Literature • ‘social identity theory’ (Tajfel and Turner, 1979) • Intergroup behaviour is based on social identification with a ‘reference group’ as a a key component of identity • Regards key aspects of our behaviour as being motivated by a tendency towards intra-group solidarity and inter group competition • Question in reference to our study is: ‘is street regarded as ‘reference group’?

7. 3. Research Questions 1. Do households on the treatment streets improve their food waste recycling more than the households on the control streets? 2. Do households who receive smiley face improves more than their baseline participation rate? 3. Do households who receive frown face improves more than their baseline participation rate? 3. Is there any cluster effect (i.e. intra-solidarity at the street level)?

8. Treatment Group with Smiley Face with encouraging text Did you know: x % of homes on Y street recycle their food waste. The average for the area is 52% With your help your street could become the best recycling street in Oldham (For more information abuo tyour food waste collection service please contact 0161 770 xxxx or e-mail as at recycle@oldham.gov.uk)

9. Treatment Group with Frown Facewith encouraging text Did you know: x % of homes on Y street recycle their food waste. The average for the area is 52% With your help your street could become the best recycling street in Oldham (For more information abuo tyour food waste collection service please contact 0161 770 xxxx or e-mail as at recycle@oldham.gov.uk)

10. Research Area • Study area: Oldham, a former mill town in the Greater Manchester area, bordering with Yorkshire. • Food waste collection from about 89,000 households • Approx. 300 tonnes of food is estimated to be recycled per month • The collected food waste is composted in Todmorden and the compost is then used on agricultural land. • The scheme was rolled out gradually from November 2008 ( completed June 2009) • No study on the performance of the scheme

11. Outcome measure • The proportion of households placing material out for collection at least once over three weeks (guidance by the Waste and Resources Action Programme, WRAP, 2006). • Two interventions to create the sense of competition • Baseline participation ratio (measured over three weeks) • 2nd participation ratio (after the first intervention) • 3rd participation ratio (after the second intervention)

12. Research Design Stratified by street size, the area (6 areas), and the baseline participation rate (50% of a smiley face group and 50% of a frown face group). 1st participation monitoring 3rdparticipation monitoring

13. So Far • “Smiley” streets (= or > mean of PR) N = 84 streets N = 2256 houses • “Frown” streets (= or < mean of PR) N = 75 streets N = 2753 houses • The first feed back delivered last week • The second participation ratio being collected next three weeks

14. Statistical Power Calculation • we expect effect sizes to be small – should be 5-10 per cent (Cotterill, John, Liu and Nomura 2009) • it is a cluster trial: Household are nested in streets • the ICC from our previous study was 0.017 • The mean number of household per street is 62, but street size ranges from 1 to 229 • With the cluster size of 62, ICC=0.017, and N of street (i.e. cluster)=318, and the significance of 0.01, we need sample N of 8,580 (our sample N=9,082).

15. Analysis Plan • Outcome: % of participation ratio • Treatment: feed back leaflet with either smiley or frown face • Analysis: • multilevel regression analysis • at the household level • the use of super output area data (deprivation rate, the proportion of ethnic minority, etc)

16. Suggestions Welcome References: Jackson, T. (2005) Motivating Sustainable Consumption: A Review of Evidence on Consumer Behavior and Behavioral Change. London: Policy Studies Institute. John, P., Smith, G. and Stoker, G. (2009) “Nudge Nudge, Think Think: Two Strategies for Changing Civic Behaviour”, Forthcoming in The Political Quarterly. Schulz, P. W., Nolan, J. M., Cialdini, R. B. Goldstein, N. J., Griskevicious, V. (2007) “The Constructive, Destructive, and Reconstructive Power of Social Norms.” Schulz, P. W. (1998). "Changing Behaviour With Normative Feedback Interventions: A Field Experiment on Curbside Recycling." Basic and Applied Psychology 21(1): 25-36. Tajifel, H. and Turner, J. (1979) “An Integrative Theory of Inter-Group Conflict. In Austin, W and S Worchel (eds) The Social Psychology of Intergroup Relations. Monterey, CA: Brooks/Cole, 33-47.