on-line book icon



table of contents





Urban Ecology Series
No. 7: Technology Assessment in the City
NPS logo




Potential Birth Rate and Survival
park bench

Malthus' predictions on population forecast the conflict between biological need for food and the technological ability to satisfy those needs. His predictions, although they have not come true, have had a tremendous influence on economics and consequent human welfare, and it is important to recognize why Malthus was wrong.

The base that Malthus used for the growth of the human population was the reproduction potential of man which is logarithmic growth. His base for food production was arithmetical, based on increases in cultivated land. Malthus calculated that populations would increase approximately according to the compound interest rate, but the food to feed such a population would increase only as additional acres of food were put into production. He assumed that there would be a constant yield of food per acre per year and his calculations proved to him that there was not enough area on the surface of the earth to develop the agriculture necessary to feed a population that was increasing geometrically. We now know that plant and animal reproduction is also geometric and that modern agriculture has increased yields of foods significantly at the same time that acreage is being reduced. That is to say, 1/7 bushel of corn planted per acre may produce 10 bushels to the acre; 25 bushels to the acre; 50 bushels to the acre; 100 or 200 or as many as 350 bushels to the acre depending upon the factors that surround the husbanding of the original 1/7 bushel of corn.

Malthus also failed to take into account the fact that the increase of knowledge that creates technology in the first place is also a geometric function. While population continues to increase geometrically, today there is the possibility for food also to increase geometrically. The rates in both cases may differ but, most important of all, our knowledge of how to control the growth of population of humans and animals and food plants is increasing geometrically

This is not to imply that the population is not or will not become a problem, not to deny that large numbers of people will die of starvation or related causes in certain areas if population is not controlled. But it does mean that the cataclysm that Malthus predicted has not occurred because all the factors involved are geometrically related functions and their interactions are more complicated than Malthus indicated.

The outlook for the city is very closely tied to the outlook for technology. Excessive, disproportionate growth is a product of uncontrolled proliferation of parts. The vast gray areas of cities are the product of mass produced, uniform structures that serve minimal purposes. These structures lack the diversity of activities and income-producing functions to make them other than dormitories. These are the areas of cities that one must leave to seek recreation and work.


Previous Next





top of page




History  |   Links to the Past  |   National Park Service  |   Search  |   Contact

Last Modified: Wed, Mar 20 2003 10:00:00 pm PDT
http://www.cr.nps.gov/history/online_books/urban/7/ue7-3.htm

ParkNet Home