Despite the proliferation of behavioral nudges across pro-environmental domains, it remains unclear whether and how these interventions interact. We study nudge interactions through a two-year natural field experiment, in which two Home Report-type social-comparison interventions—targeting household waste sorting (HWSR) and water conservation (HWR), respectively—were implemented either independently or jointly. The HWSR improved waste sorting regardless of whether the HWR was also applied. However, while the HWR reduced water consumption when implemented alone, it became ineffective when combined with the HWSR. This crowding-out effect eliminates the welfare gains from the HWR under pre-existing water tariffs that weakly internalize the environmental costs of water use. Additional evidence suggests that crowding out was most pronounced in communities with high social capital and without monetary rewards for waste sorting, and that the HWSR strengthened recipients’ moral-normative beliefs in these communities. We discuss potential crowding-out mechanisms related to attention and preferences.

Evaluations of behavioral interventions leveraging social norms typically focus on target outcomes. We studied a Home Report-type social-comparison nudge for household waste sorting in a two-year natural field experiment in China, extending the evaluation scope by examining cross-domain spillovers to the use of multiple daily resources. The nudge was delivered monthly during the first year and then discontinued. On average, it increased waste-sorting measures (d = 0.21 to 0.22) but had no significant impact on water, electricity, or gas outcomes (d =-0.05 to 0.01). Nonetheless, we found suggestive evidence that localized institutional contexts moderated spillovers: among households in communities without monetary rewards for waste sorting and with weak social capital, reductions in water and electricity usage became more pronounced and persisted after the nudge ended (d =-0.19 to-0.12). We show that even small spillovers can meaningfully affect the nudge's cost-effectiveness in mitigating carbon emissions.

Although social norms-what other people commonly do and approve of-are widely cited as a key antecedent of individuals' pro-environmental behavior (PEB), empirical research has revealed considerable variability in the norm-PEB relationship. Through a large survey of residents in Hangzhou, China, this study investigates the impact of perceived social norms on climate change mitigation behaviors, focusing on both private-sphere PEB and public-sphere environmental activism. It seeks to advance the current understanding of norm effect heterogeneity by exploring the unique roles of intrapersonal environmental beliefs and perceptions of government institutions and policy incentives in moderating normative influence. The results show that perceived social norms had an overall positive effect on both private behavior and environmental activism scales, emerging as the most powerful predictor for each. Importantly, the normative influence on the activism scale was more pronounced among individuals with higher levels of climate change risk concerns or personal moral obligation toward mitigation, and those who endorsed the quality of government more strongly, whereas on the private behavior scale, normative influence was greater among those who perceived external financial incentives for private PEBs as more salient. The moderation patterns observed based on composite scales remained consistent across individual PEBs, except that risk concerns and moral obligation also positively moderated the norm impact on one private behavior (energy saving). Overall, the findings highlight the substantial interactions between social norms and other behavioral determinants, with important implications for refining PEB theories and informing climate policies.

Environmental recall, reminding people of past pro-environmental behaviors, has been proposed as a nudge technique to promote sustainable actions. However, prior research has shown considerable variability in the effectiveness of recall nudges, and the factors moderating their impact remain unclear. This study examines the impact of recycling-based recall nudges on public support for waste prevention and disposal measures, considering the moderating roles of intervention design, social norms, and personal values. A large-scale experiment in Hangzhou, China, revealed that recall nudges can be counterproductive, reducing support for waste disposal measures when local environmental norms were strong and support for waste prevention measures when personal prioritization of self-transcendent values was low. Incorporating an internalization component in the recall nudge-linking recycling to environmental self-identity-had no effect on public support. These results challenge the effectiveness of recall nudges in fostering sustainable actions and emphasize the conditions under which such interventions may backfire.

To motivate public participation in climate change mitigation, both “carrot” policies that create positive incentives for mitigated carbon and “stick” policies that create negative incentives for emitted carbon have been widely applied. Given the joint deployment of these measures, a key question is whether they are compatible with each other. Focusing on the Low-Carbon Reward Scheme (LCRS) and carbon taxes, two prominent proposals on China's climate policy agenda, this study evaluates how one incentive policy affects public support for the other. The results of a large survey experiment with Hangzhou residents indicate a two-way crowding-out effect, wherein introducing the LCRS diminished support for the tax, albeit primarily among LCRS proponents, and introducing the tax reduced support for the LCRS. Aligning with the proposed account, crowding out was driven by a decrease in policy effectiveness and fairness perceptions. These findings reveal a contradictory relationship between carrot and stick policies at the citizen level and illuminate the underlying mechanism.

Research has shown that financially incentivizing sustainable behaviors may undermine individuals' conformity to pro-environmental social norms, but it remains unclear why and when such a crowding out effect occurs. Using data from a quasi-experiment in Quzhou, China, this study has tested crowding out in a local incentive program for household recycling and evaluated the causal mechanisms and boundary conditions of crowding out. The reward program reduced residents' inclination to conform to their neighbors' recycling behaviors and persuasion, which was driven by the lowering of the first- and second-order beliefs underlying norm conformity. The crowding out effect and pathways were particularly salient among people with high levels of environmental self-identity or community social embeddedness. Moreover, framing the incentivized behavior in an environmentally beneficial way could not mitigate crowding out. Overall, the results contribute to refined theories of crowding out and have important implications for the design of environmental policies.

Behavioral interventions that address other-regarding motivations (i.e., other-regarding interventions) are gaining momentum as promising tools to stimulate household recycling. However, previous studies have shown considerable variability in the impact of such strategies, and the factors that moderate treatment effects remain poorly studied. Using a field experiment with 7195 households in Quzhou, China, this study investigated treatment effect heterogeneity systematically based on intervention types, treatment durations, personal motivations, and social networks. Three strategies were examined, including biospheric and altruistic appeals and personalized normative feedback. We found that normative feedback outperformed other strategies in inducing household participation in recycling, that the influences of all strategies attenuated over time, and that the feedback effect was greater among recipients with weaker biospheric or altruistic concerns and those embedded within stronger neighbor networks. However, no significant treatment effects were found on the amount of waste recycled. These findings improve the understanding of the heterogeneous impact of other-regarding interventions, with important implications for the design of recycling policies. Future studies need to explore additional moderators and the effects of treatment combinations.

当前我国政府正全力推行生活垃圾源头分类,政策手段主要依赖宣传劝导与经济激励.鲜有文献检视行为助推政策对我国居民垃圾分类的影响.基于浙江省Q市近3600户家庭的田野实验数据,系统评估社会规范策略对垃圾分类行为的效果.该策略利用个体从众心理,旨在通过披露社群中大多数成员对目标行为的遵从与认可,促使受众改善行为.研究发现,社会规范策略显著提高了家庭垃圾分类参与水平,且策略效果在环保偏好或社会资本较弱的人群中更强.该策略不仅具有即时效应,在干预停止后仍发挥持续影响.进一步的成本效益分析表明,社会规范策略相比传统政策手段具有明显的成本优势.研究结果确证了社会规范策略的高效性,深化了对行为助推政策作用机理与适用条件的认识.

Applying social norm nudges to motivate household recycling is becoming increasingly popular. However, little is known about the compatibility between norm-based recycling policies and other waste management measures. Using a longitudinal field experiment with residents in Quzhou, China, we evaluated social norms messaging about household recycling in terms of its impact on recycling behavior and public support for waste prevention and harmless disposal policies. We also assessed treatment effect heterogeneity across subpopulations and persistence after messaging ended. The nudge increased recycling participation and policy support over a five-month treatment period, indicating positive direct and spillover effects. Both effects were more salient among recipients with weaker pro-environmental intrinsic motivation or community social embeddedness; however, they faded over a following five-month period when messaging was removed. Overall, the results suggest that social norm nudges improve the target behavior and facilitate policy synergy, although these benefits are neither universal nor sustainable.

气候变化关乎人类生存与发展,是当今世界面临的最大威胁之一.作为全球气候治理的重要参与国,我国持续推进减排降碳制度建设.碳减排政策的成功取决于公众支持,探析公众支持度的影响因素对提升施政效果至关重要.虽然相关文献日益丰富,但经验证据呈现高度碎片化,缺乏对潜在因素的综合性分析.同时针对我国公众碳减排政策态度的研究十分匮乏.基于此,构建了更加系统的分析框架,检视政策信念、气候变化信念、环境心理学特征、情境特征等四类维度共十一个预测因子对碳普惠与碳税公众支持度的作用.杭州市居民大样本调查结果表明,相比于碳税,民众更支持碳普惠,认为普惠制更有效和公平.政策有效性与公平性感知是影响公众支持的两个关键因素,分别解释了15.4%和17.1%的碳普惠支持度方差,21%和20.2%的碳税支持度方差,其他因素作用较弱,解释力仅在0.1%至1.1%之间.上述发现对我国碳减排政策研究与实践具有重要启示.

Prior research has shown considerable variability in the impact of financial incentive interventions on household recycling behavior, but it remains unclear which factors determine the effect of incentive policies. Building on the motivation crowding framework, this study explores how intrapersonal, interpersonal, and policy framing factors moderate the incentive effect on household recycling. Theoretical propositions were evaluated using quasi-experimental data from an incentivized recycling program in Quzhou, China. Although the program increased the recycling levels of residents, it reduced individuals' intrinsic motivation to protect the environment and, through this, exerted a negative indirect effect on recycling behavior. Such motivation crowding out was more salient among people with higher levels of environmental self-identity or self-efficacy and those embedded in stronger neighbor ties or social norms. Consequently, the incentive program was less effective in promoting recycling behavior among these subpopulations. Framing the program in an environmentally beneficial way did not affect its motivational and behavioral influences. Overall, the results extend knowledge regarding the mechanisms underlying the performance of incentive policies and the conditions that affect policy effectiveness.

It is widely believed that individuals' pro-environmental behaviors are guided by what they consider important in life—that is, by their personal values. However, much research indicates a poor relationship between values and actions, leaving an important question: when do values relate to environmental behaviors? Different from existing work that focuses primarily on the cross-national variations in value influence, this study evaluates whether and how the behavioral impact of personal values varies across localized interpersonal contexts. Through a survey of 7980 residents in 254 housing estates of Hangzhou, China, it was found that, on average, both altruistic and biospheric value prioritization scales positively predicted private-sphere environmental behavior. Further evidence suggests that the positive behavioral impact of altruistic value prioritization was only salient among housing estates with low levels of social norms, interpersonal trust, or neighbor ties. For people who were embedded in strong interpersonal influences, they showed high levels of environmental behavior regardless of altruistic value prioritization. The findings indicate interpersonal contexts to be an important explanation for the variations in the value-behavior link. Practically, they imply that social influences can be leveraged to encourage residents with weak altruistic orientations to act pro-environmentally.

Despite being a popular policy tool to promote household waste separation in local communities, role model strategies have been shown to achieve only mixed success so far. The reasons for their varied performance are not clearly understood. The present study aims to address this important issue by exploring how the influence of role models varies with the social, economic, and demographic features of local residential areas. Interrupted time series analyses of monthly observations of public participation in a large waste sorting program in Hangzhou, China have been conducted to test the theoretical propositions. The results show that role models increased the overall program participation level by 5.3%. This positive influence was greater in areas with stronger group cohesion, higher economic level, and a younger population. However, role models had a minimal effect among people with a low contribution predisposition. These findings demonstrate that the influence of role models on household recycling depends significantly on local contexts and personal idiosyncrasy, implying ways to improve the effectiveness of role model strategies in motivating residents' sustainable behavior.

Despite the widespread use of financial incentives to encourage public participation in household waste separation, recent studies have revealed the mixed success of this strategy. The present study seeks to advance our understanding of the social-contextual conditions in which financial incentives are more or less effective. Based on theories of social influence, it has investigated how program advocates, neighbor networks, and community norms affect public participation in incentivized waste-separation programs. Generalized linear mixed model analyses of more than 150,000 daily participation records for residents in 347 housing estates in Hangzhou, China have been conducted to examine the theoretical propositions. The results show that substituting ingroup members (block leaders) for outgroup agents (company staff) as program advocates increased the total number of participants. However, block leaders contributed little or even negatively to mobilizing people who had never participated previously. Levels of participation were higher among residents with stronger social networks, but lower in communities with more salient volunteerism norms. These findings illuminate the substantial interaction between financial incentives and social influences, suggesting ways to use social forces to improve incentive programs of household waste separation.

Using financial incentives to induce pro-environmental behavior may reduce pro-environmental motivation, but it remains unclear how and when such "motivation crowding out" would occur. This longitudinal quasiexperimental study investigated motivation crowding in an incentivized recycling program in Anji, China, focusing primarily on its psychological mechanisms and boundary conditions. The program reduced residents' pro-environmental motivation both in the short (after six months) and in the long run (after fifteen months), although this negative effect attenuated over time. The decrease in environmental self-identity, perceived social norms, self-efficacy, and personal ecological norms mediated the short-term crowding out effect, whereas the first three pathways declined over time. Crowding out occurred among most participants initially but persisted among people with high baseline pro-environmental motivation or self-transcendent value prioritization, and those embedded within strong local conservation norms. These findings demonstrate the demotivating influence of incentive-based environmental policies and illuminate its evolution pattern.

Waste management is a prototypical issue that requires multiple policy measures to function together. Yet, the compatibility between waste management policies is vastly understudied. In this paper, we used a longitudinal quasi-experimental methodology to identify the effect of an incentivized household recycling program in Anji, China on public support for other waste management policies. The program was evaluated six and fifteen months after it was implemented, respectively. We found that, despite its positive influence on residents' self-reported recycling behavior, the program reduced support for policy measures concerning waste prevention and harmless disposal. Consistent with the theoretical propositions, such crowding-out was driven by the decrease in personal commitment to pro-environmental goals, perceived issue importance of environmental sustainability, and perceived importance of individual contribution to environmental goods. Further evidence suggests that the crowding-out effect attenuated but did not disappear in the long run. These findings contribute to a more comprehensive understanding of the holistic relationships between waste management policies, indicating that incentive-based recycling policies can interact negatively with other waste policies by reducing public support for them.

Studies to date have shown that individual pro-environmental motivations do not always translate into pro-environmental behaviors. An important factor that modifies motivational strength is the context in which the behavior is embedded. Previous studies have largely been cross-national analyses that focus on macro-contextual factors, thus ignoring substantial variation in motivation-behavior associations at the local scale. In contrast, this study investigated the way micro-contextual mechanisms in residential areas (housing estates and communities) moderate the behavioral effects of personal values, one of the most fundamental motivations that guide individual environmental behaviors. Four contextual factors with particular attention were community environmental initiatives, social capital, local demographics, and built characteristics. The research data derived from a large-scale survey in Hangzhou, China, where community initiatives have been implemented widely to target household waste source separation. We examined our cross-level model for both waste sorting and nontarget environmental behaviors. The results showed that the associations between self-transcendent value prioritizations and waste sorting were stronger in residential areas with lower populations or community initiatives’ greater reliance on public-interest framing. Associations between value prioritizations and nontarget private behaviors were stronger in areas with lower social capital, more females, or more communal space for neighbor interactions. However, no contextual factors changed the strength of the links between value prioritizations and public behaviors. Overall, these findings highlight the significant role of micro-contextual factors in explaining the variations in motivation-behavior links. They also indicate that the characteristics of environmental behavior may moderate the dynamics between pro-environmental motivations and contextual factors further.

现有研究在分析居民环境行为的干预政策时,较多地关注干预策略对政策目标行为的影响,忽视了其对于居民其他环境行为可能产生的溢出效应.本文设计了一个田野准实验,分别检视了宣传教育和经济激励这两种垃圾分类推广策略的实施效果.为期3个月的实验结果显示,尽管两类策略均能够改善居民的垃圾分类行为,且不存在显著差异,但垃圾分类的宣传教育策略更易推动居民参与其他环保行为.进一步的中介效应分析结果显示,不断强化的环境关心度是宣传策略正溢出的一个机制,而外在激励对环保认同感的“挤出”是经济策略难以发生正溢出,甚至可能引发负溢出的一个重要原因.此类溢出效应的深入研究不仅可形成学术积累亦可优化实践部门的综合施策.

China has experienced a rapid growth of solid waste over the years, household waste source-separation is becoming a nationwide strategy for promoting recycling economy and improving urban environmental sustainability. Waste separation, however, may end in failure due to the free-rider problem similarly existing in other pro-environmental collective actions. Along with the economic and sociological/social psychological logic respectively, this study tested the effects of economic incentive and social influence, which are theoretically considered as two general solutions to domestic waste separation dilemma. One hundred and eighty-eight residents in the three communities of Hangzhou, Zhejiang Province were assigned to a control group or one of two experimental scenarios, where they were encouraged to participate in waste separation activities through either the economic rewards given on their performance, or door-stepping campaigns aimed at constructing a supportive social environment. Six-month intervention effects were analyzed and showed that economic inducement was more effective than social mobilization in promoting waste separation. Further mediation tests indicated that self-efficacy partially mediated the effects of both strategies, while personal norms were positively associated with two treatments instead of behavior demonstration. In addition, the moderating effects of several socio-demographic factors on psychological mechanisms were also explored. The findings, limitations and implications for future research and policy are discussed in the concluding section.