We consider a three sector demoeconomic model and its interdependence with the accumulation of human capital and resources. The primary sector harvests a renewable resource (fish, corn or wood) which constitutes the input into industrial production, the secondary sector of our economy. Both sectors are always affected by the stock of knowledge. The tertiary sector (schooling, teaching, training, research) is responsible for the accumulation of this stock that represents a public good for all three sectors. Labor is divided up between the three sectors under the assumption of competitive labor markets. A crucial feature of this economy is the importance of public goods--stock of knowledge and the common--which requires collective actions. Absence of collective actions describes the limiting case of hunters and gatherers. The central focus of this study is whether and what kind of interactions between the economy, the population and the environment foster sustainability and, if possible, continuous growth
