This article, based on fieldwork, explores the main economic categories of the Nzema, matrilineal farmers of South West Ghana, with the aim of reconstructing a local economic theory. The starting point is that any economic theory is logically founded in its own principles and that the internal coherence of a theory depends on its ability to represent the interests of the society to which it is applied. The work of ancestors appears as a founding idea in relation to other ideas like that of profit engendered by the work of the living.The author, however, analyses these categories, particularly emphasising the use of terminology in various contexts of daily life and in the economic lexicon as a whole, in order to trace an unitary space in which the logic of a system of thought could be considered. In order to verify the coherence of this system the author conducts a comparative analysis between the Nzema categories and the corresponding western categories organised as different theories such as neo-classical marginalism, Marx's value of work and, finally, Chayanov's theory founded on an utility concept.The central core of the Nzema's theory concerning work and profit is that the work of ancestors, first conceived as the ideological and juridical basis for the rights of their descendants over cultivable land, turns as well into a profit producer to the advantage of the living under the condition that it should be materialised as a means of production like, for example, the coconut trees, which were planted by the ancestors, and now produce a profit for their descendants.
DEPENDÊNCIA DA TRAJETÓRIA, IRREVERSIBILIDADE E O PAPEL DA HISTÓRIA NA SELEÇÃO DE TECNOLOGIAS