XVt is the level of exports; WDt, is the index of world demand for traditional
exports; CMt, is the indicator of the competitiveness of agricultural exports; DVt, is an
index of diversification of agricultural exports; ut, is the stochastic error of the model
and t, is indexing time in discrete yearly periods. The prefix “L” before each variable
indicates that we have used the logarithms instead than the levels of these variables.
Thus, we can use the coefficients a1, a2 and a3 directly as elasticities and capture possible
non-linearities in the relationship among these variables.