Nudges, Subsidies or Regulation? Estimating Effects of Policy Choices and Mixes on Digitalization: Evidence from China’s Aquaculture Industry

Aquaculture digitalization is increasingly regarded as a crucial pathway to improving productivity, sustainability, and resilience in the fisheries sector. Policy instruments intended to foster this digital transformation—such as substantial subsidies and stringent regulatory mandates—often face constraints stemming from fiscal limitations, administrative burdens, and implementation inefficiencies. Behavioral interventions (nudges) represent a potentially effective and less resource-intensive alternative, yet their capacity—individually or in conjunction with moderate subsidies and regulatory measures—to foster aquaculture digitalization remains empirically underexplored. Drawing on survey data from 254 fish farmers in the lower Yangtze River region and employing a combination of principal component analysis (PCA), ordinary least squares (OLS) regression, Propensity Score Matching (PSM), and Gradient Boosted Trees (GBT) techniques, this study finds that: (1) Social nudging has a robust and consistent positive effect on digital transformation; (2) The effects of subsidies and regulations are heterogeneous and context-dependent; (3) The negative interactions between nudging and constraints, as well as between nudging and subsidies, are context-dependent and tend to inhibit digital transformation; (4) Policy effects display marked heterogeneity across different contexts, particularly with respect to sales channels, external pressures, producers’ transformation capabilities, and the scale of aquaculture operations. These findings deepen the understanding of how behavioral and structural policies interact in agricultural digitalization, emphasizing that effective policy should combine financial and regulatory measures with efforts to strengthen farmers’ digital awareness and behavioral adaptability.