Pro-Environmental Waste Receptacle Labeling Can Increase Recycling Contamination

Early research has suggested that point-of-disposal signage and recycling receptacle modifications can increase recycling rates (Austin et at, 1993). However, the once steady increase in overall recycling rates over the past few decades appears to be stalling, with the most recent data showing only a 0.6% increase from four years prior (US EPA, 2014). At the same time, there has been a substantial rise in the rate of contamination from placing unrecyclable materials in recycling receptacles, which has created significant additional costs in the follow-up processing (Groden, 2015). In four field and online experiments, we show that point-of-disposal signage aiming to encourage recycling (such as the term "landfill" on garbage bins) could also increase recycling contamination. Prior research suggests people are generally averse to being wasteful (Bolton & Alba, 2012) and that failure to recycle could engender feelings of guilt (Viscusi et al., 2011). Therefore, we reason that labeling garbage bins with pro-environmental terms could make emotions evoked by the negative consequences of garbage more salient and thus increase the likelihood that individuals will incorrectly categorize unrecyclable items as being recyclable. In study 1 (и = 259 observations), as part of a new product sampling event by a well-known brand of coffee and related products, we offered passersby on a university campus the opportunity to sample a carbonated beverage (served in an unrecyclable foam cup). The study site featured two swing-top bins to dispose of their used sample cups. The label on one bin was experimentally manipulated to be either "Landfill" or "Trash". The other bin was labeled as "Recycle" in both conditions. The rate of (incorrect) recycling increased to 54.5% (67 out of 123 cups) when the "Landfill" label was used compared to 25.0% (34 out of 136 cups) for the "Trash" label (X2(l) = 23.58, p < .001). In study 2 (n = 122 observations; minimum of 33 observations per condition), during a separate beverage sampling event several weeks after the study 1, using the same procedures and unrecyclable cups as study 1, we tested additional types of labels including (i) control: "Trash" and "Recycle", (ii) avoid garbage: "Don't Destroy the Earth, Trash Less" and "Recycle", (iii) encourage recycling: "Trash" and "Save the Earth, Recycle More". Compared to the control condition, the recycling rate of the foam cups significantly increased in the avoid garbage condition (19.6% vs. 60