8 Economic Dynamics environmental economics already had a body of literature. What happened in the 1970s and 1980s was that it became a recognised sub-discipline. Economists who had considered questions in the area had largely conFned themselves to the static questions, most especially the questions of welfare and cost–beneFt analysis. But environmental issues are about resources. Resources have a stock and there is a rate of depletion and replenishment. In other words, there is the inevitable stock-ﬂow dimension to the issue. Environmentalists have always known this, but economists have only recently considered such issues. Why? Because the issues are dynamic. Biological species, such as Fsh, grow and decline, and decline most especially when harvested by humans. ±orests decline and take a long time to replace. ±ossil fuels simply get used up. These aspects have led to a number of dynamic models – some discrete and some continuous. Such modelling has been inﬂuenced most particularly by control theory. We shall
This is the end of the preview. Sign up
access the rest of the document.