Food waste produces methane in landfills, accounting for 1.5–2.0% of net global anthropogenic greenhouse gas emissions in 2010. In developing countries 40–65% of household waste can be food waste, especially from preparation, since pre-prepared food is less common. Different waste management strategies are used worldwide to get householders to separate out their food waste, including the restriction of permitted times and places for depositing household waste (e.g. 6–7pm daily at kerbside, only). Here we evaluate a Certain Time, Certain Place (CTCP) intervention used across a sample of six communities randomly allocated from a cohort in one district of Shanghai. Mixed methods are used, with directly-measured tonnages pre- and post-implementation, and site observations and open interviews of stakeholders to elicit perceived relevant factors. Quantitative results show no statistically significant impact on waste sorting performance. Relevant themes which emerged are: time period arrangements; supervision of waste stations; attitude of the assistant cleaners. These are shown to be related to known determinants of Inconvenience, Role clarification, and Positive interactions. Action Planning and Stakeholder Engagement are suggested as mitigators of Inconvenience, but Distance not found relevant. Such deconstruction of policy elements into scientific factors allows a clear scientific perspective: that this CTCP program was almost pure CT only, which increased Inconvenience without giving overall benefits from increasing supervision. Only one community had CP involved, and its performance increased significantly, suggesting CP should be studied further.
In sum, this Certain Place, Certain Time recycling program was actually CT, and is not recommended for increasing food waste sorting performance. The more direct linking of policy elements to scientific factors is suggested as useful for better future design.