Does Engagement in One Pro-Environmental Behaviour Cause a Spillover Effect: The Case of the Plastic Bag Levy

Does Engagement in One Pro-Environmental Behaviour Cause a Spillover Effect: The Case of the Plastic Bag Levy

Introduction

The anthropogenic impact on the environment is often adverse, significant and stems from a multitude of actions and behaviours. Increasing global awareness of how humanity adversely impacts the environment has led to the implementation of many initiatives designed to reduce the scope and the magnitude of specific adverse impacts, an example of which is the plastic bag levy (Nielsen et al., 2019). These targeted campaigns have the goal of changing specific products or behaviours to encourage the adoption of those that considered more environmentally friendly, in the plastic bag example this would be to re-use plastic bags or to use bags made of an alternative material (Evans et al., 2013). However, changing one behaviour in isolation is not going to led to a substantial reduction in environmental degradation overall, instead it is necessary that all behaviours are considered with regards to reducing their adverse impact on the environment. Thus arises the question of whether engagement in one pro-environmental behaviour, such as bring your own bags to the supermarket, causes a spillover effect whereby pro-environmental behaviours are engaged in within other aspects of the individuals life (Verfuerth and Gregory-Smith, 2018).

What Drives Engagement in Pro-Environmental Behaviour?

There have been numerous studies published that have attempted to understand what factors drive engagement with pro-environmental behaviours (Lynn, 2014; Moser, 2015). There is a need to understand why individuals engage in pro-environmental behaviours so that environmental strategies can be developed based on these factors and thereby increase the likelihood of adoption and proliferation within society (Abrahamse, 2019). Arguably one of the most notable concepts that has arisen from studies of pro-environmental behaviour is the identification of the attitude-behaviour gap (Bernardes et al., 2018; Wiederhold and Martinez, 2018). The attitude-behaviour gap is the term that describes the difference between the environmental attitude that an individual perceives that they have and the pro-environmental behaviours that they engage in (Bernardes et al., 2018). It has been reported in several studies that many individuals who profess to be conscious of the environmental and desire to reduce the adverse impacts that they have on the environment, frequently do not actually exhibit pro-environmental behaviours within their life (Kennedy et al., 2009). One potential explanation for this is that pro-environmental behaviours are typically not engaged in due to altruism, rather they are commonly motivated by reason that are considered to be more selfish (Kennedy et al., 2009). An example of this is seen in the plastic bag levy. Before the plastic bag levy there was a general awareness that plastic bags could present a substantial environmental hazard due to the time that plastic takes to degrade and the plastic contamination of specific environments, such as microplastics in the oceans (Tziourrou et al., 2021). Although there was a general public awareness of this issue there was limited voluntary action taken to reduce plastic bag use. However, when plastic bag levies are introduced the number of individuals purchasing single use plastic bags dropped significant in many areas (Kish, 2018). Thus, the motivation for the public engagement in reducing the consumption of single use plastic bags was not through an altruistic concern for the environment but rather due to the expense to themselves of having to purchase single use plastic bags.

It has been postulated by some researchers that if an individual engages in one pro-environmental behaviour, then this may lead them to engage in other pro-environmental behaviours, termed the spillover effect (Verfuerth and Gregory-Smith, 2018). However, if pro-environmental behaviours are not typically altruistic and instead are motivated by personal gain and other more selfish factors, then it is unlikely that a spillover effect will occur. The example of single use plastic bags is used to examine whether a spillover effect occurs.

Does a Plastic Bag Levy Result in Spillover Pro-Environmental Behaviours?

The use of a financial motivator has resulted in a significant reduction in the consumption of single use plastic bags in the vast majority of locations where it has been implemented, there are specific cases where a plastic bag levy has failed, such as Botswana, however this type of failure is rare (Madigele and Mogomotsi, 2017; Mogomotsi et al., 2019). However, whilst the introduction of a plastic bag levy has generally resulted in reductions in the consumption of single use plastic bags, it has not completely eliminated the use of this type of bag, for example, He (2012) found that in China a plastic bag levy resulted in a new plastic bag use reduction of 49%. The reasons that He (20