This paper studies the natural-resources element in the t h e o r y o f p o p ulation growth over the very long run. In the context o f the stock o f land and M a l t h u s i a n crises in earlier times, the model shows how resources have b e c o m e more available rather t h a n more scarce, even as p o p u l a t i o n and income have increased.
The paper sketches a m e c h a n i s m which, a d d e d to the M a l t h u s i a n system, leads to entirely different conclusions t h a n does the M a l t h u s i a n system. Using the illustration o f food and land, change in knowledge and hence in the stock of resources is m a d e a function of the stock o f knowledge and the price of resources. The speed of a d j u s t m e n t depends on the economic and social climate for the development o f new knowledge. P o p u l a t i o n growth first raises food and land prices, which then stimulate the creation o f new resources, eventually leading to less scarcity o f resources and lower prices t h a n originally prevailed.
T h a t is, p o p u l a t i o n growth creates new problems which in the short run constitute a d d i t i o n a l burdens which, in the longer run, lead to new developments that leave people better off t h a n if the problems had never arisen.