"The Limits to Growth" is a brief, forceful, easily read polemic which has already generated many times its own weight in enthusiastic encomia and equally strong condemnations.[i] It advances a familiar, indeed fashionable, thesis. The goals and institutions of our present world society stimulate population growth and production increase at a rate that cannot be sustained. Further, and perhaps less familiarly, we are now about a generation from the point of no return, after which the world must suffer a catastrophic drop in numbers and wealth, no matter what is then done to restrain further growth. The argument is presented with a sufficient panoply of graphs, flow diagrams, references to the World Model and the new discipline of System Dynamics, and invocations of the computer to produce an aura of scientific authority for the conclusions. They have the additional weight of the endorsement of a prestigious private international group of respected businessmen, officials and academics, The Club of Rome, in a commentary appended to the study and signed by its executive committee. It is my contention that the authors' analysis is gravely deficient and many of their strongest and most striking conclusions unwarranted. None the less, it draws attention to a number of difficult and important problems which must be faced, including the question of whether its whole approach is helpful or harmful in dealing with these real problems.
The backbone of the argument of "Limits" is simple, and requires little elaborate intellectual machinery to develop. Many significant variables that characterize our global society, in particular population and industrial production, have been growing exponentially over the last century, that is, at a constant percentage rate, and thus showing a greater and greater absolute increment each year. The processes that determine this persistent growth at constant (roughly) percentage rates lie deep in the structure of our social order, and unless we deliberately make drastic changes in it, they may be expected to persist and continue to generate exponential growth in the