1、Chapter 1 Visions of The Future Contents: 1. Introduction 2. The basic pessimist model 3. The basic optimist model 4. The road ahead 5. Issues 1. Introduction 1.1The Self-extinction Premise 1.2The Use of Models 1.3Thinking About The Future 1.1The Self-extinction Premise Thomas Malthus foresaw that p
2、opulation growth would outstrip the growth of food supply, resulting in starvation and death, if reproduction was encouraged. 1.1The Self-extinction Premise Modern ecologists have suggested that ecological disruption would occur with disastrous consequences for humanity if the “carrying capacity” （承
3、载能力）（承载能力） of environment is exceeded widespread. 1.1The Self-extinction Premise Economists have been concerned with topics such as exhaustible resources（可（可 耗竭资源）耗竭资源） and pollution. Now, weve come to better understand the relationship between humanity and the environment and how that relationship
4、affects, and is affected by, economic and political institutions. 1. 2 The Use of Models In economics, as in most other disciplines, we use models to illustrate complex subjects, such as relationships between the economy and the environment. In using these models, we should also be sensitive to thei
5、r limitations. Limitations of models: Models are simplified characterizations of reality. Models may yield conclusions that are dead wrong. Models are useful abstractions that should always be viewed with some skepticism. 1. 3 Thinking About The Future The basic pessimist model(悲观模型悲观模型) The basic o
6、ptimist model(乐观模型乐观模型) 2. The Basic Pessimist Model 2.1 Conclusions of Pessimist Model 2.2 The Nature of the Model 2.1 Conclusions of Pessimist Model The first suggests that within a time span of less than 100 years with no major change in the physical, economic, or social relationships that have t
7、raditionally governed world development, society will run out of the nonrenewable resources on which the industrial base depends. When the resources have been depleted, a precipitous collapse of the economic system will result decreased food production, and a decline in population as the death rate
8、soars. The second conclusion is that piecemeal approaches to solving the individual problems will not be successful. The third suggests that overshoot and collapse can be avoided only by an immediate limit on population and pollution, as well as cessation of economic growth. 2.2 The Nature of the Mo
9、del The dominant characteristic of the model is exponential growth（指数增长）（指数增长） coupled with fixed limits. Exponential growth in any variable implies that the absolute increases in that variable will be greater and greater each year. The higher the rate of growth in resource consumption, the faster a
10、 fixed stock of it will be exhausted. 2.2 The Nature of the Model Several resources are held in fixed supply by the model. This basic structure of the model is in some ways reinforced and in some ways tempered by the presence of numerous positive and negative feedback loops. Positive feedback loops
11、(正反馈回路)are those in which secondary effects tend to reinforce the basic trend. A negative feedback loop(负反馈回路负反馈回路) is self- limiting rather than self-reinforcing. 3. The Basic Optimist Model 3.1 Conclusions of the Optimist Model 3.2 The Nature of the Model 3.1 Conclusions of the Optimist Model The
12、Simon vision of the future concludes: The standard of living has arisen along with the size of the worlds population since the beginning of recorded time. And with increases in income and population have come less severe shortages, lower costs, and an increased availability of resources, including a
13、 clearer environment and greater access to natural recreation areas. And there is no convincing reason why these trends toward a better life, and toward lower prices for raw materials, should not continue indefinitely. 3.2 The Nature of the Model First, historically human resourcefulness has always
14、overcome both scarcities of resources and environmental problems associated with economic activity. Second, no compelling reason why those trends cannot continue indefinitely into the future. 3.2 The Nature of the Model Several observations to bolster Simons argument. Food production is not likely t
15、o be a limit for increased agrarian or agro-production. Natural resources have not become more scarce over time. Apparent shortages are due more to problems with human behavior than to any physical lack of availability Pollution levels have declined as population and incomes increased. 3.2 The Natur
16、e of the Model What are the driving forces behind these outcomes? Simon suggests that our economic and political systems respond to scarcity in ways which eliminate or diminish its impact. 4. The Road Ahead The differences between the pessimist and optimist model depend on how human behavior is perc
17、eived. If intensifying pressure on the environment results in a behavioral response which intensifies the pressures, pessimism is justified. If the human responses either currently are reducing those pressures or could be reformed so as to reduce those pressures, then optimism may be justified. 4. T
18、he Road Ahead The field of environmental and natural resource economics has become an important source of ideas for coping with environmental problems. Not only does the field provide a firm basis for understanding the human sources of environmental problems; this understanding provides a firm found
19、ation for crafting specific solutions to these problems. 5. Issues Is the problem correctly conceptualized as exponential growth with fixed, immutable resource limits? Does the earth have a finite carrying capacity? If these limits do exist, have they been measured correctly or, as Simon argues, has
20、 the Beyond the Limits team been rather myopic in the way they treat resources? How can the carrying-capacity concept be operationalized? Do current levels of economic activity exceed the carrying capacity? 5. Issues How does the economic system respond to scarcities? Does the process involve mainly
21、 positive feedback loops? Would it intensify or ameliorate any initial scarcities? Is the overshoot-and collapse syndrome an accurate portrayal of the future? What is the role of the political system in controlling these problems? In what circumstances is government intervention necessary? Is this i
22、ntervention uniformly benign, or can it make the situation worse? What is an appropriate role for the executive, legislative, and judicial branches? 5. Issues Many environmental problems involve a considerable degree of uncertainty about the severity of the problem and the effectiveness of possible
23、solutions. Can our economic and political institutions respond to this uncertainty in reasonable ways? 5. Issues Can the economic and political systems work together to eradicate poverty while respecting our obligations to future generations? Or does our obligation to future generations inevitably c
24、onflict with the desire to raise the living standards of those currently in absolute poverty? Can short- term and long-term goals be harmonized? How? What does the need to preserve the environment imply about the future of economic activity in the industrialized nations? In the less industrialized nations? Further reading: The Limits to Growth Beyond the Limits Our Common Future
