Activation of these two channels therefore consists of simulating the variations observed or estimated for said international transfers. For the first group, we can speak of exports constrained by external demand (type 1), while the second group represents exports largely constrained by internal supply (type 2). The variation in export demand in relation to its initial level is therefore conditioned by the ratio of the world prices for these exported products and their free on board (FOB) export prices, as well as the elasticity of export demand among foreign trade partners.