1. Biophysical Limits to Economic Growth The Malthusian Perspective

2. Introduction For the rest of this quarter, we will attempt to systematically explore the association of ecological limits and economic growth. The main questions that would be addressed are: Can we expect unlimited economic growth in a world endowed with “finite” resources? If ecological limits are important factors in determining future trends of...

3. continue... …economic growth, what steps or precautions should be taken in order to avoid transgressing these biophysical limits? Three approaches: –The Malthusian Perspective –The Neoclassical economic perspective –The Ecological economic perspective

4. The Simple Malthusian Model Basic Postulates of the Malthusian doctrine of resource scarcity and economic growth: –Resources are scarce in absolute terms -- resources are available in “finite” amount. –If uncontrolled, the tendency of human population is to grow exponentially. –Technology should not be perceived as the “ultimate” escape from the problem of resource scarcity.

5. continue... Thomas Malthus (1766- 1834) An Essay on the Principle of Population as Its Affects the Future Improvement of Mankind (1798) Basic Assumptions of the model: –The total amount of land available for agriculture is immutably fixed –The growth of population is limited by the amount of food available for subsistence. –Human population will invariably increase where the means of subsistence increase.

6. continue... Malthus’ famous doctrine or assertion: …if not prevented by some checks, the tendency is for the population to grow geometrically (2, 4, 8, 16, etc.) while the means of subsistence grows arithmetically (1, 2, 3, 4, etc.) Unless this tendency of ever-increasing imbalance between the grrowth of population and the means...

7. continue... …of subsistence is resolved by “moral” restraints (negative checks), in the long run “vice” and “misery” (positive checks) will ultimately repress the superior power of population to a level consistent with means of subsistence. Explain this using Figure 6.1 from the text.

8. continue… Criticisms of the Malthusian Simple Model: –It ignores the institutional factor that affect population growth –Overlooks the important role that technology plays in ameliorating resource scarcity –It could be considered ecologically naïve. Does not go beyond the acknowledgement of the finiteness of resources.

9. The Ehrlich-Commoner Model The model starts with the premise that all human activities modify the natural environment to some extent. In its simplest form, this model can be mathematically expressed as follows: I = P x F

10. continue... The variable “I” represents the total environmental effect or damage measured in some standard unit, “P” is a variable representing population size in terms of head count, and “F” is an index that measures the per capita impact (damage) to the environment. F = f[P, c, g(t)]

11. Paul Ehrlich Model Population, P, plays a primary role in explaining the impact human activities have on the environment and resource use. I = P x F Two factors –Increase population itself –impact on per capita impact (increase in F) do to the Law of Diminishing Marginal Product. That is, F, is an increasing function of population.

12. continue... In conclusion, if other factors are held constant, successive addition of people would require increased use of resources, such as energy, water, fertilizer, pesticides, and other renewable and nonrenewable resources. Thus as population continued to grow, the per capita impact, in terms of pf resource depletion and environmental deterioration, would increase successively.

13. Per Capita Consumption, C If population, consumer preference and technology are held constant, an increase in per capita consumption, c, would only result form increased use of resources (hence, environmental damage). [Explain using graph] Some scholars, for example, Durning, asserts that over consumption is the main culprit of environmental deterioration and resource depletion.

14. Commoner’s Model Modern technology is the main source of environmental problems. Commoner views modern technology as being ill-conceived and not wisely applied in the production of goods and services. Why? See next slide

15. continue... Because the decisions to change the composition of economic input and output is made purely on the basis of technical efficiency (increase per capita production), rather than the impacts these decisions ma y possibly have on the environment. (See page 126 in the text)