Análisis gráfico de las devaluaciones cambiarias

Abstract

Current graphical depictions of devaluation-effects on a trade balance seem to show infinitesimal movements by means of a diagrammatic apparatus of curves and shifts. It is argued here that the latter is inconsistent with the former, though should be useful in analyzing finite devaluations. This is accomplished by developing an approach based on known geometrical properties of expenditures elasticities and a graphical measure of devaluation ratios. There follow two formulae which translate MARSHALL-LERNER condition into finite terms, i.e. e+k>1 and em+k>1, respectively. That amounths to give up the uniqueness property of MARSHALL-LERNER formulae of being the same whatever the currency units employed, which is explained on the ground of differential effects of a currency-depreciation upon economic plans and the size of devaluation itself.