Modeling tools, developed jointly by UNCTAD and FAO. the Agricultural Trade Policy Simulation Model (ATPSM) is a global trade model designed primarily for simulating agricultural trade policies, notably in the context of the UR Agreement on Agriculture. The primary objective is thus to assist trade negotiators, policy analysts and others interested in the assessment of the effects of various negotiating proposals and of the Agreement itself once negotiated. An unique advantage of this model over other models of this type is that it covers virtually all countries, including LDCs.