Orientation du progrès technique et développement durable

We consider an economy where successive generations consume two different kinds of services, produced respectively from artificial and natural assets. Technical progress makes it possible to expand the artificial assets, but not the natural ones; on the contrary, the latter may be eroded by a careless implementation of the technical progress. It is shown that, if every generation displays a sufficiently high degree of altruism, growth is both sustainable and compatible with the Rawlsian criterion of distributive justice: if then appears that the Rawlsian approach is not confined to the "dull prospects" that Solow has deplored. It is also shown that it is possible to derive the Rawlsian sequence from the maximization of a discounted sum of levels or welfare. It is always the case that the discount factors are strictly less then one -- Koopman's equivalence theorem is not contradicted in this respect -- but are dependent on the intertemporal pattern of technical progress.