Data limitations did not allow for the inclusion of agricultural machinery. This index is a sub-component of the World Bank’s Logistics Performance Index. These indices, drawn from Kee, Nicita and Olarreaga (2009), provide the best country coverage available to date for both tariffs and NTMs. Their computation is described in more detail in Annex 2. The advantage of weighted indicators of trade barriers is that they give a more realistic view of the actual constraints faced by individual countries in practice. However, a key drawback is that such indicators mask the impact of prohibitive tariffs and, more generally, tend to give a lower weight to a barrier, the higher it is.