Using Commitment and Communication to Increase Grass Cycling in Suburban Neighborhoods

Cobern, M. K., Porter, B.E., Leeming, F.C., & Dwyer, W.O. (1995). The effect of commitment on adoption and diffusion of grass cycling. Special Issue: Litter control and recycling. Environment and Behavior, 27, 2, 213-232.
First, a literature was conducted to identify the most effective behavior change tools to encourage grass cycling. Then, three homogeneous suburban neighborhoods were observed for four weeks to determine the number of bags of grass placed at the curb each week. Following this observation, the neighborhoods were randomly assigned to one of three groups based on strategies uncovered during the literature review: commitment, commitment/communication or control. In the commitment group, heads of households were approached and asked to sign a commitment card to leaving grass clippings on their lawns. Also, this group was given a certificate of appreciation. In addition to signing the commitment form, the commitment/communication participants agreed to talk to their neighbors about grass cycling. By acting as an agent of communication, it was hoped that these participants would foster social diffusion in their neighborhoods. After four weeks, participants were informed that the commitment period was complete. Conversely, the participants who served as a control group were never contacted or given information about grass cycling. At the end of the four week intervention, the number of grass filled bags placed at curbside was measured for 4 weeks, and again after one year.

Before the introduction of the behavior change tools, grass bags were present at curbside 50% of the time. After four weeks of intervention, the commitment group had reduced this proportion to 30%. Moreover, the commitment/communication group were bagging their grass clippings only 10% of the time. When program evaluation occurred one year later, these two groups continued to grass cycle more than the control group. In addition, neighbors of the commitment/communication group were grass cycling significantly more than the control group.
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