about seven percent; those who received the utility's version, not at all. A 1979 U.S. Department of Energy mailing to every household in New England achieved sig- nificant results including a plastic showerhead flow restrictor with each pamphlet. Apparently, Stern says, the flow restrictors were like a "foot in the door." Once people used them, they were more receptive to other conservation measures.
Consumers also seem to be willing to conserve as long as they feel that they are not...