* Distance<sub>producer</sub> - the distance between the producer NUTS-location to the centroid of the country;
+
* Distance<sub>inter-country</sub> - the distance between the country centroids of the producer and reseller;
+
* Distance<sub>warehouse</sub> - the distance between the centroid of the country and the reseller warehouse. Usually the location of the reseller warehouse will be assumed to be the same as country centroid, so set to zero;