Harald Heinrichs · Pim Martens Gerd Michelsen · Arnim Wiek Editors

2.3 Plastic Bags and Loss Aversion
Because plastic bags are petroleum products with harmful environmental impacts 
(Derraik 
2002
), they have been banned in San Francisco and Los Angeles. In 2010,
Washington D.C., began charging fees for disposable bags, using part of the funds
to support cleanup efforts of the heavily polluted Anacostia River. Homonoff (
2012
) 
examined that program and the difference between a five-cent fee for plastic bags 
and a five-cent reward for reusable bags. Her analysis showed the fee to be effective. 
The reward reduced plastic bag use by only 2.4 %, whereas the tax reduced plastic 
bag use by 43.5 %.
J. Harlow et al.

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What could be responsible for such a large difference with equal monetary incen-
tives? First proposed by Kahneman and Tversky (
1979
), loss aversion postulates 
that we are more sensitive to the prospect of losing an amount of money than the 
prospect of gaining the same amount of money. The implications of loss aversion 
extend far beyond the decision of whether to use a plastic bag. Field (
2009
) showed 
that law students’ career choices were dramatically affected by loss aversion. Lower
tuition produced 36–45 % more students pursuing public interest law than debt
remittance after graduation. Loss aversion is a powerful, well-evidenced behavioral
tool with broad applications for making consumption more sustainable.
2.4 Cafeterias and “Shaping the Path”
Another common example of applying behavioral science to make consumption
more sustainable comes from public health. Rozin et al. (
2011
) reduced overeating 
by demonstrating the power of the dining environment on food consumption. Subtly
changing ease of access to certain foods or reducing the size of serving utensils 
reduced food intake by an average of 8–16 % (Rozin et al.
2011
). The researchers 
go on to imply that altering the dining environment could also be leveraged to 
improve the quality of food eaten (think strategically placed fruits and vegetables). 
Heath and Heath (
2010
) call this type of environmental design “shaping the path.”
There are plenty of examples of successfully shaping the path of dining environ-
ments to alter food consumption (Hanks et al. 
2012
; Schwartz et al.
2012
; Kallbekken 
and Sælen
2013
). Redesign of a decision environment (think of a cafeteria as a deci-
sion environment for what to eat) is a potent way of influencing consumption with-
out wading into politically charged or otherwise controversial issues. Shaping the
path can direct consumption toward products that are environmentally and socially 
responsible simply by changing the ways “easy options” are presented to 
consumers.
In summary, behavioral research provides insights into how tools of influence
can be used to support sustainable consumption – by providing knowledge (towel 
reuse messages), incentives (plastic bag tax), or an environment conducive to sus-
tainable consumption (cafeteria design). For an extensive list of behavioral science
insights on “nudging,” consult the Stirling Behavioural Science Blog/Nudge
Database (Egan 
2013
).
• Task : Reflect on the approaches to incentivizing sustainable consumption pre-
sented above – changing the default, using social proof, leveraging loss aver-
sion, and shaping the path. Are your consumption decisions influenced by these 
principles, and if so, how? Try to think of examples of unsustainable consump-
tion patterns. How might you use one or more of the approaches discussed to 
promote sustainable consumption in these cases?
24 Consumption and Sustainability

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