One of the benefits of encouraging consumers to form desirable habits is that it can create positive spillover: People like to be consistent, so if they adopt one sustainable behavior, they are often apt to make other positive changes in the future. After IKEA【C1】_____a sustainability initiative called Live Lagom, it studied the sustainability journey in depth among a【C2】__group of its customers. The company found that【C3】__people may begin with a【C4】__step—such as reducing household food【C5】__—they often move on to act in other domains, such as energy conservation. IKEA【C6】__a snowball effect as well: People would begin with small actions and build to more meaningful ones. For example, buying LED light【C7】__might lead to wearing warmer clothing and turning down the thermostat, changing curtains and blinds to【C8】__heat loss, insulating doors and windows, buying energy-【C9】_____appliances, installing a programmable thermostat, and so on.

It is important to remember that【C10】_____spillover can occur too: A sustainable action may lead someone【C11】__subsequently behave less sustainably. Termed licensing by researchers, this occurs【C12】__a consumer feels that an initial ethical action【C13】__permission to behave less【C14】__in the future. In one example, researchers found that people who had performed a virtual green shopping task were less likely to behave prosocially than those who had performed a virtual conventional shopping task. In other examples, people use more paper when they can show that they are recycling.【C15】_____, car models with increased fuel efficiency may lead people to drive more miles.

Companies can take【C16】_____to lessen the risk of negative spillover. They can ensure that the first sustainable action is particularly effortful,【C17】__seems to build commitment. In one study, participants who had engaged in token support for a cause that demonstrated to others that they were “good people”—such as joining a “public” Facebook group or【C18】__an online petition—were less likely to engage in a private task later. However, those who privately joined a Facebook group or signed a petition were more likely to see the cause as reflecting their true values and to follow【C19】__. Note that this differs from the earlier example of giving pins to hotel guests who choose energy-efficient options, because in that study wearing a pin was【C20】_____tied to a commitment to perform a sustainable action.

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