**7. Conclusions**

This paper contributes to the growing body of the GM food literature by explicitly investigating consumer preference and WTP for mandatory labelling conveying the health and safety attributes of the GM foods. The results signify that consumers recognize the importance of investing in the mandatory labelling conveying safety information. This suggests the efforts and policy strategies for enhanced mandatory labelling will benefit Chinese citizens. This is encouraging because financial and technical assistance from the governmen<sup>t</sup> can target certain interest groups, rather than distributing the resources to satisfy all groups. It may be more interesting to agency leaders to consider the specific WTP amounts for the three types of enhanced mandatory labelling information. Allergen presence labelling and nutrient and compositional change labelling can better help consumers understand the potential risks and benefits of the GM foods, but neither is highly ranked in terms of the WTP values. Instead, the traceability codes show the highest WTP value. This is interesting because the traceability codes may help consumers know where the products come from, but it would not inform them of the potential risks and benefits. Conversely, it may be the nature of the right-to-know of traceability codes that makes them more valuable to the public. While governmen<sup>t</sup> agencies are responsible for improving mandatory GM food labelling managemen<sup>t</sup> for the benefit of the public, it is critical to include publicly linked policies, such as consumer WTP for enhanced labelling, to gain more support from the public.

Policies encouraging consumers to make purchase decisions that match personal preference are inherently desirable, regardless of the end-user characteristics or process attributes. These policies should be cost-effective. Unfortunately, our results do not present the costs or benefits of instituting an enhanced mandatory labelling program. A policy decision to impose enhanced mandatory labelling should recognize both its benefits and costs, while considering whether the practitioners are equipped or facilitated to implement the policy. The research does not conclude that an enhanced mandatory labelling program should be instituted. Rather, the findings provide guidance on how an enhanced mandatory labelling program should look like if such a program is warranted. Nevertheless, further research is needed, including calculating the additional costs and evaluating the benefits. Additionally, this paper is restricted to GM soybean oil, while future research can expand this approach to other GM foods.

**Supplementary Materials:** The following are available online at https://www.mdpi.com/article/10 .3390/foods10040736/s1, Table S1. Prices of the "X" brand edible oil in the same size.

**Author Contributions:** Conceptualization, M.Z., Y.F. and C.C.; Data curation, M.Z.; Formal analysis, Y.F.; Funding acquisition, M.Z.; Investigation, M.Z., J.C. and C.C.; Methodology, M.Z., Y.F., J.C. and L.C.; Project administration, C.C.; Resources, C.C.; Software, J.C. and L.C.; Writing—original draft, M.Z., Y.F., J.C. and L.C.; Writing—review & editing, C.C. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the National Natural Science Foundation of China (71603129; 71673139).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study. **Data Availability Statement:** Not applicable.

**Conflicts of Interest:** No conflict of interest exits in this manuscript, and it has been approved by all authors for publication.
