Harald Heinrichs · Pim Martens Gerd Michelsen · Arnim Wiek Editors

2 Examples of Incentivizing Sustainable Consumption
2.1 Electricity Choices and Default Options
Pichert and Katsikopoulos (
2008
) examined home electricity consumption choices. 
They point out that 50–90 % of survey respondents in the USA, UK, and EU stated
a preference for consuming renewable energy sources. Despite this, rates of adop-
tion of renewable energy sources are abysmal, in the range of 0.4–1.0 %.
Conventional wisdom speculated that reluctance to adopt renewable energies is 
related to socioeconomic factors. However, Pichert and Katsikopoulos (
2008
) 
turned to psychology and behavioral science, hypothesizing that the electricity 
source chosen was a function of how electricity options were presented. The authors 
asked a simple question: what happens to “green electricity” when it is the default 
option? The results of two field and two laboratory studies show that simply 
changing the default source from “gray” to “green” results in a significantly higher 
percentage of customers buying green electricity.
24 Consumption and Sustainability

---

296
The main behavioral science principle in this experiment is the “default option” 
made popular by Thaler and Sunstein’s (
2008
) book Nudge. The default option is 
what individuals “choose” by doing nothing when presented with a decision. 
Changing defaults has been wildly successful in cases ranging from organ donation 
(Johnson and Goldstein 
2003
) to retirement savings (Madrian and Shea
2001
). 
Making default consumption options more sustainable is a potent method for mak-
ing consumption more sustainable.
2.2 Towels and Social Proof
There are over 4.5 million hotel rooms in the USA, and a hotel with 150 rooms can
save about 6,000 gallons of water a month by reusing towels and linens (Cassingham
2006
). The overall potential savings is 180 million gallons of water every month in 
the USA.
To nudge guests to reuse towels, Schultz et al. (
2008
) drew from research on the 
power of social proof to affect behavior (Cialdini 
2009
). Social proof tells us that
the behavior of others is positive reinforcement for our behaviors. Schultz et al.’s
study compared the effect of different messages on hotel guests. Messages that 
communicated both the value of conserving resources and the number of other 
guests who reused towels to help with conservation were the most effective in 
towel-use reduction (Schultz et al.
2008
). In a similar study, such messages com-
municating that “the majority of guests in this room reuse their towels” reduced 
towel usage more than hotels’ traditional appeals based on resource conservation
(Goldstein et al. 
2008
). A recent study by Shang et al. (
2010
) concludes that 
responses to such social marketing programs are most positive when savings from 
the program are donated to charity. The more sustainable consumption becomes, the 
stronger the social proof feedback and support will become. Making sure that social 
proof feedback is built into sustainable consumption strategies can strengthen 
impacts and quicken sustainability transitions.