The accumulation and substitution effects of multi-nation certified organic and protected eco-origin food labels in China

We conduct a choice experiment to explore Chinese consumer willingness to pay (WTP) for milk with multi-nation organic labels. We also consider the interaction between these labels and the novel Protected Eco-Origin Product (PEOP) certification as well as different brands. Two types of multi-nation organic certification are examined: ‘double certification’ (i.e., carrying both the Chinese and EU organic labels) and ‘triple certification’ (i.e., carrying Chinese, EU, and U.S. organic labels). Compared to the Chinese organic label alone, consumers increase their WTP for double and triple organic certification, but the marginal WTP decreases for an additional organic label suggesting a negative accumulation effect. Meanwhile, organic and PEOP labels are substitutes, with the substitution effect stronger for higher number of organic labels. Welfare changes with various combinations between multiple organic and PEOP labels, as well as consumer preference heterogeneity across labels are analyzed, providing implications on producer decision-making, policymaking, and consumer benefit analysis with respect to organic and ecolabel certification in general.