In a recent model of growth developed by Lucas (Lucas, R., 2009. Ideas and growth. Economica 76, 1–19), a continuum of people interact in a random manner and copy each other’s productive ideas when it is economically beneficial to do so. This paper extends the Lucas model by assuming that...

Between 5000 BCE and 1800, the population of the world grew 120-fold despite constraints on the total amount of land available for production. This paper develops a model linking population growth to increasing productivity driven by random innovation and diffusion. People are endowed with a set...

A unified growth model is presented in which productivity growth is driven by learning-by-doing. We show that the growth rate of productivity is an increasing function of the share of capital. It is assumed that the industrial sector has a higher capital share than the agricultural sector and...