1. Ahlburg’s article describes the impact Julian Simon had on the world of academic thought concerning population and its consequences. Simon, referred to as a ‘revisionist,’ greatly expanded the scope of the population growth debate, through his works that involved discourse on population, development, and public policy. His work brought such attention as it refuted the popular alarmist belief held by neo-Malthusians, as he believed that the long run positive affects of population growth would outweigh the short run negative affects. Simon’s famous book The Ultimate Resource shows that he was a population optimist. He believed that the markets would pick up on signals to avert catastrophe, and through our population growth we would be generating a creation of knowledge that would provide the innovation required to overcome any obstacles. Furthermore, he criticized those who adamantly sought to reduce growth rates, as at that point they are reducing the inherent value of human life.
Ahlburg gives Simon the credit he is due, but then he applies some of Simon’s concepts to the 1980s and finds there to be a negative association between population growth and economic growth. Ahlburg postulates that one should not look to the past and apply those trends to the future, as all places are unique both in time and place, this creates discontinuities that prevent the application of past trends. He goes on to suggest that the findings for the 1980s are the result of the saving rates being adversely affected, the decline in returns to existing technologies in agriculture, and environmental degradation. So despite acknowledging the vast contribution Simon has had, Ahlburg’s article disagrees with his arguments, and concludes that the slowing of population growth will likely be advantageous.
2. This paper seeks to develop a simple three-equation model of economic growth that will define the growth path of real capita GNP implied by the data. This model was applied to data for 100 countries found in the 1967 UN Statistical Yearbook. Their initial findings showed that the growth path did not rise indefinitely (limit was around $5,300), and there was no unstable lower equilibrium. The model also tended to underestimate growth rates for poor countries, while overestimating the growth rates of rich countries. Furthermore, modification of the parameters merely speeded up the rate at which the limit was approached. Comparison with historical trends of different countries produced varied results, leading to conclusion that there are systematic errors in the model. However, the model shows there to be less change in growth rates as nations develop, and that there is significant correlation between growth rates and investment ratios. But despite this conformity, the authors acknowledge the shortcomings of the model, such as the exclusion of such factors as education and pollution.
3. This paper is an expansion of the previous one, and uses the same equations applied to 88 countries with 1991 data. The same patterns can still be identified. Richer countries are still investing not only more but a larger fraction of total output than poorer nations. Populations are still growing more slowly than in DCs than in LDCs. Growth rates are also still influenced positively by the fraction of total output invested, and negatively by population growth. Furthermore the model identifies a limit twice the current US GNP per capita (at time of writing) as well as a threshold GNP per capita around $400 above which growth is possible. At the same time, the limitations and errors can still be seen, the Asian Tigers do not conform to the model, and there is less change in growth rates as nations develop historically than would be indicated by the cross-section data. Despite these shortcomings the authors believe that the model stands the test of time.
1. "Julian Simon and the Population Growth Debate" by Dennis A. Ahlburg, in Population and Development Review, June 1998, Vol. 24, No. 2, pp. 317-327.
2. Paul M. Sommers and Daniel B. Suits, "A Cross-Section Model of Economic Growth" in the Review of Economics and Statistics, Vol. 53, 1971, pp. 121-128.
3. Sandeep K. Gupta and Paul M. Sommers, "A Simple Cross-Section Model of Economic Growth Stands the Test of Time", forthcoming.