3.1.2. Farmers' Knowledge

In the simulation experiments, pig farmers were the primary actor in economic activity. Their knowledge and cognitive capacity were the main factors affecting their estimation of expected

return [23], thus influencing their use of VAs. According to the literature research and the author's field observations, the farmers' knowledge was summarized into three categories: knowledge of VA use specification, knowledge of hazards of VA residues, and knowledge of relevant laws and their penalties, represented by *ϕi*1, *ϕi*2, and *ϕi*3, respectively. As the five-point Likert scale was used in the measurement of the farmers' knowledge level, it was assumed that *ϕi*1, *ϕi*2, and *ϕi*<sup>3</sup> take a value in [1,5], respectively, where 1 means no knowledge and 5 means complete knowledge. Since the knowledge level of each farmer is not exactly the same in reality, the values were given for *ϕi*1, *ϕi*2, and *ϕi*3, respectively, in the simulation.
