We set up an endogenous growth model in which the efficiency of both capital and fossil energy can be improved, whereas the efficiency of one alternative energy source is limited. With capital and energy as complements, there exist two steady states: one stagnant where energy is fully derived...

"This radical new reading of the eighteenth-century British theorist Thomas Robert Malthus's Essay on the Principle of Population exposes his narrow understanding of food production by examining subsistence activities such as hunting, herding, and gardening. In broadening our conception of human...