We show that, contrary to a widely spread error, when the savings and the population growth rates are constant, an unstable equilibrium cannot exist in a neoclassical model, because it would imply an increasing average productivity of capital and therefore a negative marginal productivity of...

Individual and collective security are among the gauges of civilization, and at the same time they constitute necessary conditions for its progress. Their systematic pursuit is relatively recent among nations: prompted by the dreadful lessons of the 20th century, they took their present shape...