 Natives could "volunteer" to work on the plantations or face conscription, working for $1.50 per month.Salazar's system of slavery prompted 500,000 Angolans to flee, creating a labor shortage, which in turn created the need for more slaves for the colonial economy.Marcello Caetano, Salazar's Minister of Colonies, recognized the inherent flaws in the system, which he described as using natives "like pieces of equipment without any concern for their yearning, interests, or desires".