Triple-hurdle model analysis of the factors influencing biogas digester building, use and processing by Chinese pig farmers

Because of the pollution associated with pig manure, pig farmers are being encouraged to adopt environmentally friendly manure management solutions such as biogas digesters. However, as the correlations and influencing factors associated with the different manure disposal stages remain unclear, these solutions have failed to positively change farmer disposal behaviors. Therefore, this paper constructed a triple-hurdle model to empirically analyze the pig farmer manure disposal behaviors and the associated relationships under the belief that the three stage biogas digester decisions were driven by structurally different processes. This paper adds to the literature in three ways: (1) it provides a dynamic framework that identifies pig farmer manure disposal behaviors; (2) it applies a recently developed econometric method that corrects for conditional correlations between error terms; and (3) proves that certain factors might have opposite impacts in different behavior stages. It was found that cultivated land area and farm income ratio had statistically significant positive impacts on biogas digesters construction behavior but a negative influence on the farmers' use of the biogas digesters. Farmers who joined a cooperative were found to be statistically more likely to be biogas digester users, and the unconditional expected share of the actual treated manure was significantly higher. This study can assist policymakers in formulating and implementing strategies to encourage greater biogas digestor use by pig farmers.