Descripción: “...Through a documentary study, a historical journey is made from Purchasing Power Parity developed by Gustavo Cassel, representative of the Stockholm school, the vision of the neoclassical synthesis expanded by Dornbusch, of the Mundell Fleming Model, and the Harrod-Balassa effect- Samuelson, to expose more recent empirical and econometric representations through models of reduced or uniqual forms and structural models of exchange rate determination that add analytical and mathematical instruments, many of them with microeconomic foundations, highlighting the different factors that support each focus or model.Keywords: real exchange rate, equilibrium real exchange rate, exchange misalignment, purchasing power parity ...”