Multiple pathways of institutional environment driving the reduction of veterinary antibiotic overuse: Evidence from dairy farmers in Heilongjiang Province, China

Reducing veterinary antibiotic overuse is a critical strategy for protecting the ecological environment, ensuring food safety, safeguarding public health, and maintaining biosecurity. Currently, not only formal government institutions but also informal institutions have become critical in reducing the overuse of antibiotics by farmers; however, the literature on this topic remains limited. To advance research in this field, this study draws on micro-survey data from 141 dairy farmers with more than 100 cows in Heilongjiang Province, one of China's major dairy-producing regions. The institutional environment (IE) is conceptualized along three dimensions-regulative environment (RE), normative environment (NE), and cognitive environment (CE)-and the study employs Partial Least Squares Structural Equation Modeling (PLS-SEM) and Fuzzy-Set Qualitative Comparative Analysis (fsQCA) to investigate the mechanisms and pathways through which the IE and farmers' sense of responsibility (SR) influence the reduction of veterinary antibiotic overuse (RVAU). The results indicate that: (1) IE has a significant positive effect on RVAU by dairy farmers, and by enhancing their SR, it further promotes RVAU. (2) RE, NE, CE, and SR interact in multiple configurations, resulting in two key pathways that drive a high RVAU level: the "NE-SR" linkage type and the "RE-CE-SR" driving type. Among these, the "NE-SR" linkage type is slightly more applicable than the "RE-CE-SR" driving type, with high SR playing a crucial role in enhancing RVAU levels. There are two conditional configurations that lead to a non-high level of RVAU, namely the "NE-CE-SR" restriction type and the "RE-NE-SR" restriction type. (3) The pathways for improving RVAU vary across different farm scales. NE and SR generally impact the RVAU level across different farm scales, while RE has a significant impact on medium-scale farmers. Based on these findings, it is necessary to improve the control mechanism, optimize institutional coordination, innovate promotional strategies, and pay attention to scale differences to effectively promote farmers' reduction of antibiotic overuse.