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Researchers at University of Tsukuba have found that different types of social connections are associated with household waste separation through different pathways. A study in Osaki Town, Japan, showed that close neighborhood ties are associated with positive attitudes and social expectations regarding recycling, while broader social networks are more directly linked to participation in waste separation.

Tsukuba, Japan—Waste separation and recycling are essential to achieving a circular economy and sustainable resource management; however, the long-term success of well-established recycling systems depends on the continued participation of local residents. This study examined how social capital, defined as social relationships characterized by trust, reciprocity, and mutual support, is associated with waste separation behavior.

This study focused on a municipality that has maintained one of the highest recycling rates in Japan for many years. Using data from questionnaires administered to local residents, the researchers analyzed how different forms of social capital relate to residents' attitudes, intentions, and waste separation behavior within a psychological framework based on the Theory of Planned Behavior.

Residents with stronger neighborhood-based social ties, known as bonding social capital, were more likely to actively engage in waste separation. These local ties were positively and indirectly associated with waste separation via more positive attitudes toward recycling and a stronger perception that proper waste separation is expected by others in the community. Conversely, bridging social capital, which reflects broader social connections outside residents' immediate neighborhoods, was associated with waste separation behavior through a different pathway: a direct association with behavior. These findings highlight the link between community relationships and environmentally responsible behavior through multiple social and psychological pathways. They also suggest that sustainable waste management depends on recycling infrastructure, institutional systems, and strong social connections within communities.

In aging communities, measures to foster neighborhood ties while encouraging the participation of younger generations may help sustain community-based recycling efforts in the long efforts.

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This study was supported by JSPS KAKENHI Grant No. 23K28288.

Original Paper

Title of original paper:

When neighbors recycle together: Social capital and sustainable waste management in Osaki Town, Japan

Journal:

Journal of Material Cycles and Waste Management

DOI:

10.1007/s10163-026-02755-5

Correspondence

Professor KAIDA Naoko
Institute of Systems and Information Engineering, University of Tsukuba

Related Link

Institute of Systems and Information Engineering