Paper, plastics and penalties

For decades, curbside recycling has been a fixture in neighborhoods across the United States, empowering citizens to protect the environment and reduce waste. But it’s a system that relies on consumers to know what items are recyclable and which ones can contaminate the delicate ecosystem.

New research from faculty at The Ohio State University Max M. Fisher College of Business examines the effectiveness of one tool that recycling companies, organizations and municipalities can use to limit contamination: curbside recycling audits.

“Our objective was to examine how different forms of curbside audits impacted households’ recycling performance,” says Erin McKie, assistant professor of operations and business analytics at Fisher and the report’s lead author. “Specifically, we wanted to find out how curbside feedback of varying severity influenced recycling quality (as measured using household contamination rates) and participation (as measured using recycling cart set-out rates).”

McKie, along with Aravind Chandrasekaran, the Fisher distinguished professor of operations, and Sriram Venkataraman, associate professor at the Darla Moore School of Business at the University of South Carolina, authored the study, which was published in Production and Operations Management. 

In the following interview, McKie discusses the study’s results and how the research can help bolster recycling in the U.S.

Q: I’ve heard most of our recycling ends up in landfills. Is this true?

Erin McKie (EM): If recycling is too expensive compared with other disposal methods, such as landfilling, then, yes, materials may be landfilled. However, the direct landfilling of recyclables is not as widespread of a phenomenon as often suggested. Curbside recycling programs generate nearly $1 billion in community revenue and recover millions of pounds of materials for reuse annually.

At the same time, however, markets for recyclable materials are extremely dynamic, and profit margins can be very thin. According to industry experts, approximately 100 curbside recycling programs have been canceled in the U.S. in recent years, with even more scaling back. Hence, the threat of program cancellation resulting in landfilled materials is very real and always present.

Q: What are the biggest threats to recycling?

EM: Contamination is one of the biggest cost drivers and, accordingly, one of the biggest threats to the recycling industry. It is caused by household-level sorting errors, like when unaccepted or non-recyclable materials are placed in recycling bins. Roughly 20 to 25 percent of collected recyclables are contaminated.

Removing contaminants to meet industry quality standards costs material recovery facilities (MRFs) millions of dollars per year in operational costs. These costs can stem from increased plant downtime—a moderately sized MRF can lose $10,000 for every 10 minutes it is shut down—increased labor sorting fees, spoilage and more.

Contamination often is what causes thousands of tons of otherwise recyclable material to be burned or landfilled, thereby polluting the environment and costing communities millions in foregone recycling revenues. Contamination can make recycling a revenue-negative effort.

Another factor that leads communities to abandon recycling is lack of program participation.

For recycling to be profitable, residents must both recycle well and recycle often.

Q: So, to get a better idea of how well households are recycling, you reviewed curbside audits conducted by a consulting group in Columbus, Ohio. During the auditing process, inspectors examined recycling bins for items that didn’t belong. What did the auditors do when they found a contaminant?

EM: If a contaminant was found, then one of two possible outcomes occurred: 

1. The household received a cart warning, wherein their recycling bin was tagged with an information card highlighting which items were improperly recycled. We refer to this as an “information-only approach” to correct household behaviors. 
2. The household received a cart refusal, wherein their recycling bin was tagged with an information card and the household’s recycling bin was not emptied. In this case, the resident was required to remove the contaminant to receive service in the future. We refer to this approach as an “information-plus-penalty approach” to correct household behaviors.

Q: Did people take offense at being penalized for trying to recycle something that isn’t recyclable?

EM: No. We found the information-plus-penalty mechanisms, or cart refusals, were very effective. Specifically, households that received this punitive feedback reduced contamination severity by 59 percent and were 75 percent less likely to commit a future violation.

Additionally, we found that household recycling participation behavior did not decrease after households received a punitive feedback mechanism. 

Q: Was this surprising?

EM: Yes. While the use of curbside auditing mechanisms is promising, recycling industry stakeholders, such as recycling education organizations, MRFs and local community leaders, remain divided on the use of cart audits. Several stakeholders fear that punitive mechanisms, such as the cart refusal in particular, will discourage participation. 

However, we found that the opposite occurred: Households recycled more when they received either form of feedback, including cart refusal. 

Prior to our analysis, we were unaware of any industry or academic study that had examined the granular, household-level effect of these feedback mechanisms to settle this debate. 

Q: What were some of the caveats from the research?

EM: While we show that the cart refusal mechanism is effective, to be leveraged, a municipality first must have the political willpower to implement this type of punitive measure. 

• Cart refusal is more effective when administered to households with moderate-to-high education and income levels and low-to-moderate population densities.
• It is most effective at reducing the presence of aspirational contaminants, such as to-go containers or plastic bags. We did not find evidence that suggested it would work well on more egregious contaminant categories like trash or bagged and bulky items.
• Cart refusal is less effective when administered in areas with older populations and high population densities.

Q: How can this research help recycling organizations and municipalities with their efforts?

EM: In short, the results from our research show that information in the form of cart refusals can help increase the amount of material captured in addition to improving captured quality.

By using the most effective feedback mechanism identified through this study, either exclusively or paired with a courtesy warning, recycling stakeholders can better protect the future of U.S. community recycling programs.

Erin McKie is an assistant professor of operations at The Ohio State University Fisher College of Business in Columbus, Ohio. Her research is focused on sustainable supply chains, circular economy and the interface between marketing and operations. McKie’s research team collaborates with companies to extract valuable insights on recycling. Organizations interested in learning more can contact her at mckie.5@osu.edu.