“…To obtain shadow prices, we use the multi‐equation modelling framework of pollution‐generating technologies discussed in several papers (Dakpo & Ang, 2019; Førsund, 2017; Førsund, 2021; Ray et al, 2017), which finds its origin in Frisch (1965). This modelling has been used to measure performance while accounting for environmental pollution from firms (Boussemart et al, 2019; Lozano, 2015; Murty & Nagpal, 2019; Zhao, 2016), and to a lesser extent from farms (Chambers et al, 2014; Dakpo et al, 2017).…”