Chile's northern border region has historically been a territory of circulation for the Bolivian population that has been motivated by job opportunities and trade alternatives in the regional economy. While Tarapacá has not been the main destination of Bolivian migration, it has formed part of the migratory field, especially for the Aymara, who live in the areas closest to the border, and for Bolivians in general since the 1990s. From strong migration during the saltpeter expansion cycle (1880-1930), the area moved to a more silent and less visible migration limited to the altiplano and upper Andean valleys and then to a process that was more integrated into the international context beginning with the creation of the Tax Free Zone in Iquique at the end of the 20th century.