Increasing the Uptake of Composting at the American University of Beirut Campus

Executive Summary

Nudge Lebanon, in collaboration with the American University of Beirut’s (AUB) Environmental Health, Safety and Risk Management office and students from the Economics department, designed and implemented a behavioral insights intervention to increase the uptake of composting among faculty residents on campus. The intervention, which consisted of a commitment, reminders, salience and hassle simplification, resulted in a 61.5% increase in the uptake of composting in the treatment buildings compared to 14% in the control building.

Policy Challenge

“Composting is a biological process in which organic waste such as food and other organic material is decomposed by bacteria, fungi, worms and other organisms under controlled aerobic conditions.”^[1] Composting is an environmentally-friendly method to reduce organic waste. The end result of composting is the accumulation of partially decayed, nutrients-rich, organic matter that can be used to enrich the soil for gardening, urban agriculture and organic farming.

In an effort to promote sustainable initiatives, and in light of the residents’ willingness to compost^[2],  the AUB, in collaboration with Compost Baladi, initiated a campus-based composting project in November 2018. Nine large containers, “Earth Cubes”, were installed in two locations that served three residential buildings located on AUB’s lower campus. Four Earth Cubes were installed next to Building A, serving 30 apartments, while the remaining five were installed between buildings B & C, serving 24 and 34 apartments, respectively.^[3] A bin filled with dry leaves was placed next to each group of Earth Cubes.^[4]

In addition, residents of these buildings were invited to a training session to learn how to compost, as well as collect bins and disposable paper bags to place their sorted organic waste. Households that did not attend the training session were asked to pick up their bins and paper bags from the Environmental Health, Safety and Risk Management office.

Despite these efforts, the utilization rate of the composting bins was extremely low. There are many behavioral challenges that may have contributed to the intention-action gap, including hassle, forgetfulness and lack of social norms. To address these challenges and increase the uptake of composting, Nudge Lebanon, in collaboration with students from the AUB, designed and implemented a behaviorally-informed intervention consisting of several tools: a) simplifying the steps required to compost, b) asking residents to commit to composting, c) placing green footsteps from the building entrances leading towards the Earth Cubes, d) sending biweekly emails reminding residents to compost. In addition, salient posters were placed in the lobby of the buildings to remind residents to compost.

Intervention Design

To assess its impact, the intervention was implemented in Buildings B and C only (henceforth, the treatment buildings), while Building A maintained the business-as-usual approach (henceforth, the control building). The intervention was implemented in 4 stages:

1. Stage 1: A door-to-door survey was conducted in order to measure the number of households composting at the baseline.
2. Stage 2: Following the collection of surveys, households in treatment buildings were offered individual bins to sort their organic waste at home. They were also provided with a leaflet that included three simple steps to compost, as well as a pledge to help the AUB community save the planet. Residents were asked to place a tick in a check box to affirm their commitment to compost.

In addition, green footsteps were painted from the main entrances of the treatment buildings, leading to the Earth Cubes. Percentages were added beside the footsteps to indicate proximity to the bins. To complement the green footsteps, posters were placed in the lobby of the treatments buildings prompting residents to compost today.

Finally, following feedback from the surveys, the locks of the Earth Cubes were replaced to make them easier to open.

3. Stage 3: Households in treatment buildings received biweekly email reminders sent by the housing department at AUB.
4. Stage 4: After four weeks of implementation, a door-to-door survey was conducted again to measure the number of households composting.

Results

Two outcomes were measured before and after the intervention: a) the number of households that claimed to be composting, and b) the volume of organic waste disposed in the Earth Cubes.^[5]

According to the results, the estimated volume of organic waste disposed in the treatment bins, during the four-week intervention period, increased by 61.5% (from 643L to 1040L) compared to a 14% increase  in the control bins (from 277L to 317L). [6]

These findings were supported by the results of the end-line survey which revealed that only 2 out of 9 surveyed households in the control group were composting, compared to 20 out of 31 households surveyed in the treatment group.^[7],

Conclusion

Having the intention and the know-how to compost may not be enough to prompt action. Households may experience a number of behavioral barriers that could prevent them from composting on a regular basis. This intervention reveals that the combined use of nudges such as commitments, reminders, salience and hassle simplification could offset some of these barriers to increase a household’s uptake of composting.

Despite the success of this intervention, it does not offer insights on its effectiveness in the long run. Future interventions should measure the effects over a longer period to assess its effectiveness on habit formation.

Endnotes

[1] Composting. (n.d.). Retrieved from http://livinggreen.ifas.ufl.edu/waste/composting.html

[2] Based on the results of a survey suggesting that a significant proportion of faculty residing on campus

[3] Building A was geographically separated from Buildings B and C.

[4] To facilitate the composting process, an equal amount of dry leaves should be added when organic waste is being disposed of in the compost bin.

[5] The volume of organic waste disposed in the Earth cubes was estimated using the observed waste height in the bins.

[6] A Mann-Whitney Wilcoxon test showed that the results were significant at 1% confidence level (p-value = 0.0016))

[7] At the baseline, 4 out 14 control households were composting, compared to 12 out of 40 treatment households.