Variables capturing natural trade barriers and cultural or historical proximity come from the CEPII Gravity dataset: distance, contiguity, common language, former colonial links, common legal system and time difference. We consider this as a proxy for the fact that the value added traded between two countries i and j can be influenced not only by the direct importance of trade facilitation implementation in i and j, but also by the status of trade facilitation implementation characterising all countries k,. ( We follow the treatment procedures used in Achard and al. (