The English Plastic Bag Charge and Behavioural Spillover: A Field Experiment, Diary Study and Secondary Data Analysis

One of the greatest challenges of sustainable development is to find effective and acceptable policies that can foster meaningful and lasting behaviour change. While many people can be encouraged to recycle by providing adequate facilities, it is very difficult to change other waste-related habits. At the same time, governments have become less willing to introduce expensive regulation. Consequently there is great interest in low-cost, socially acceptable policies that help support behaviour change. The plastic bag charge (PBC) that is going to be introduced in England in October 2015 can be seen as such an instrument. Previous research has shown that PBCs are popular, easy to implement, and can successfully reduce plastic bag use (Convery et al. 2007; Poortinga et al. 2013).

Some policy-makers hope that the benefits may go even further, in that changes to a relatively simple behaviour may lead to other, more ambitious changes (Defra 2008). The first behaviour change may serve as a 'foot in the door' to help establish experiences that may subsequently lead to other changes - also known as behavioural spillover (Thogersen & Crompton 2009). This holds the promise that significant cost-effective changes can be made without burdensome regulation. Indeed, previous research conducted by the applicants found significant changes in environmental identity after a similar carrier bag charge was introduced in Wales in October 2011 (Poortinga et al. 2013). However, there is very little evidence of behavioural spillover in the environmental domain.

The overall aim of the project is to generate high-quality field-experimental and qualitative evidence of lifestyle change and potential BSO resulting from the English PBC. The introduction of the English PBC is a unique opportunity to conduct this research, as it is a relatively simple instrument that aims to change a specific and common waste-related habit. However, little is known about the lifestyle impacts of a PBC. The observation that even small charges produce great changes, suggests that a PBC acts as a 'habit disruptor' that forces shoppers to rethink their plastic bag use, rather than as an economic instrument (Poortinga 2013). Furthermore, as 'bringing your own bag' is a highly visible and symbolic behaviour, it may change how people perceive themselves in terms of waste-consciousness. This then may lead to other waste-related behaviour changes.

The project builds upon previous research of the applicants (Poortinga et al. 2013), but will expand the scale and depth of the study by conducting a mixed-method longitudinal programme of work, including (1) a novel field experiment, (2) a qualitative diary study, and (3) secondary data analyses, to examine in detail how effective a PBC can be; how it works; and whether it can produce behavioural spillover. It will use Wales and Scotland as comparators to allow the effects of the English PBC to be separated from other trends in carrier bag use and waste practices. Furthermore, the proposed project uses secondary data analysis and a behaviour mapping exercise to identify the most likely candidates for behavioural spillover.

The project constitutes an ambitious multi-method programme of work that will create an in-depth understanding of lifestyle change and behavioural spillover following the introduction of a plastic bag charge. The beneficiaries of the research are diverse, encompassing academic peers from the social science community, and a range of non-academic users of the research. The non-academic beneficiaries of this research include: i) policy-makers and practitioners at the national level (Defra), ii) devolved administrations and regional bodies (Welsh Govt Scottish Govt, Northern Ireland Executive); iii) organisations engaged in waste and environmental quality (e.g. WRAP; the 'Break the Bag Habit' campaign coalition); and iv) interested publics.

Ensuring that the research impacts beneficially upon such a diverse array of users is a challenge. However, the research team has a strong track record and experience in research engagement, and has already started to engage key users at the pre-submission stage. We are open to critical feedback from experts and policy makers external to the project team, hence our intent to form a Project Advisory Board that will provide assistance in identifying any theoretical and practical policy gaps in the work. Letters of support from relevant bodies provide evidence of our engagement with potential users of the research prior to submitting the proposal, and our plans for a targeted process of engagement with key users of the research.

Findings will be disseminated through high-impact academic journals (e.g. Global Environmental Change; Journal of Environmental Psychology) and will be discussed at symposia and conferences (e.g. International Association for People-Environment Studies conference; International Congress of Applied Psychology). Beyond the publication of results in academic journals and presentation at symposia/conferences, there are three key routes by which non-academic beneficiaries will hear about and benefit from the proposed research:

1) Dissemination Meetings (London, Cardiff) and the production of a key findings brochure.
The principal results will be launched via a major policy dissemination meeting at the Royal Society to academic and policy communities. The focus of the Understanding Society Survey analysis on the Welsh charge warrants a separate workshop for Welsh policy makers in Cardiff. Both events will not only allow for communication of results by the project team but also for stakeholder participation, with attendees encouraged to reflect critically on both our data and methodologies. The practitioner brochure will present headline findings and practical implications, and will be disseminated widely beyond this event, through the networks of participants at the launch and downloadable via our website.

2) Project Advisory Board
An advisory board with six members will provide critical feedback on the design and direction of the research. The board will comprise policy stakeholders, NGOs, and two independent academic advisors. Academic members will advise on the theoretical and methodological integrity of the research, while involvement of government and NGO representatives ensures that the research remains policy relevant. The advisory board also constitutes a vehicle for the direct dissemination of results to users of the research.

3) Public Discussion Blogs and Website
Traditional methods of academic publishing are no longer sufficient with a growing demand for research to have a more profound impact on policy and society. Interactive social media (e.g. Website, Twitter, blogs) will be used to make the findings available to the wider public, where it is free to be read, discussed, and used. These interactive forms of communication are used to enter into a conversation with publics and parties that previously would not have had access to the research. This opens up the research for feedback to make a contribution to broader civil society.