<p>The mounting problem of waste is a challenge to sustainability. This study examined socioeconomic, infrastructural, and psychological factors associated with waste management behaviors, focusing on age cohort differences.&#xa0;Binary logistic regression was used to analyze data from an online survey conducted by the Korea Environment Institute (N = 1,071; individuals born between 1956 and 1999; 52.8% women). Waste management behaviors were assessed with questions about whether respondents were recycling and avoiding using disposable products.&#xa0;The findings showed that older cohorts were more likely to recycle and avoid using disposable products compared to younger ones, with cohort differences more pronounced in voluntary pro-environmental reduction behaviors than in mandatory recycling behaviors. Among those born in the 1950s/60s, the rate of avoiding disposables was 1.6 times higher than those born in the 1990s. Response efficacy—the perception of how well a given behavior will reduce a given problem—was strongly associated with recycling among this group, while environmental attitudes were not.&#xa0;These results suggest that psychological components such as response efficacy should be considered when developing social policies related to waste management behaviors. Furthermore, the study implies that older cohorts, particularly baby boomers, can serve as change agents for climate change in their communities.</p>