These attributes reflect key drivers of the buying decision. It is im-
portant to note that all levels refer to the respective level at the farm
gate. The levels for the buyer–supplier relationship have been set
according to Kotler (1982), Kotler and Armstrong (2010), and Jang
and Olson (2010), who describe different stages of integration within
the food value chain. The attributes are sorted according to the four
spheres Technology, Economics, Society and Nature