We study transitions between nonrenewable and renewable energy forms at di!erent development stages of an economy. It is shown that in the historical context the emphasis on energy production may evolve from renewables to nonrenewables and back to renewables. Typically both energy forms are used simultaneously. Along the equilibrium path, nonrenewable resource consumption may increase and their...

green water and blue water; renewable and nonrenewable water resources; water allocation and water allocation

This emergy-based urban economic account provided a historical portrait of the urban economy and its structures to understand the overload of the biosphere`s assimilative capacity. The basic situation of the urban economy, involving the indigenous resources base, emergy consumption patterns, emergy exports and imports, were investigated, accounted and discussed. Using a series of ratios and ind...

In this paper, we introduce a new multimode project scheduling problem, taking into account finish-to-start precedence relations among project activities as well as renewable and nonrenewable resources constraints. We suppose renewable resources are hired and not accessible in all time intervals of a project. In other words, there is a presumed release date as well as a mandated due date for ea...

Technological Change, Depletion and the U.S. Petroleum Industry*** A common claim in the nonrenewable resource literature is that improvements in technology may largely offset the effects of increasing scarcity over time. This study provides perhaps the first empirical evidence on this issue by analyzing the determinants of the average finding cost for additional petroleum in the U.S. over the ...