Saturday, February 19, 2011

Malthus Part I

On Monday students in my Economics and Sustainability class will meet two suitors: Neo-Malthusians and Neo-Institutionalists. Then, a love triangle, more intense than the smoldering Twilight Series, will ensue for their views on population growth. The lecture aims to paint a solid historical picture of Reverend Thomas Malthus and his thoughts on population. Then, fast-forward to the modern debate over population, the environment, and the economy. Part I involves the post today: Who was Thomas Malthus? Why was he interested in population? And, what did he actually say about population?

Thomas Malthus was born to country gentry in 1766 and received an impeccable education throughout his youth winning many awards at the Jesus College at Cambridge until he graduated in 1788. He entered the Anglican Priesthood following graduation and famously penned An Essay on the Principle of Population in 1798. According to Landreth and Colander (History of Economic Thought 4th Ed.) the effects of population interested Malthus for three reasons: 1) In 1790 food prices in Britain were increasing, 2) There was growing concern over the movements toward urbanization, 3) Malthus believed that by demonstrating strain on resources through population increases he could reveal a flaw in arguments of utopian theorists (direct interventions wouldn't work because population growth would cause diffusion of public goods and larger labor supply). The publication was an immediate success and caught the attention of numerous intellectuals from a variety of fields. The premise of the Essay can be summarized in Malthus' own words:

I think I may fairly make two postulata. First, that food is necessary to the existence of man. Secondly, that the passion between the sexes is necessary, and will remain nearly in its present state. These two laws ever since we have had any knowledge of mankind, appear to have been fixed laws of our nature . . . Assuming then, my postulata as granted, I say, that the power of population is indefinitely greater than the power in the earth to produce subsistence for man. Population, when unchecked, increases in a geometrical ratio. Subsistence increases only in an arithmetical ratio. A slight acquaintance with numbers will show the immensity of the first power in comparison to the second. (Malthus 1798/1986, 8–9)

The central point was that if his assumptions were correct population would outstrip food supply. By no means did he believe that his assumptions were iron clad. For example, he believed that if technology improved the food supply would also improve. Landreth and Colander absolve him of his assumption about technological improvement noting that no economists have developed a good model of when and how technological innovation might occur. Economic historian Ross Emmett notes that:

The assumption that Malthus discounted technology is based in part on the difference between the way he stated his population principle the way he discussed the means by which humans escape its consequences.
While the principle is stated with elegant, mathematical precision, the means of escaping its consequences are identified in “conditional” statements: “If” humans find more arable land, or “if” they adopt new technologies, “then” food production can increase enough to feed the ever-increasing population. Conditional statements are weaker than positive statements such as “the power of population is indefinitely greater than the power in the earth to produce subsistence for man” (Malthus 1798/1986, 9). But they have the same force if the author thinks the condition will be satisfied.

This misunderstanding led some people to grant economics the title of the "Dismal Science" TANGENT!: Although dismal science was talked about in reference to Malthus' ideas it was in fact coined earlier in a different context. Because economists believed that people of all races were productive and capable of trade, others who believed blacks to be inferior deemed economics the "dismal science"

Malthus however did not make such doomsday predictions, instead, he was cautiously optimistic. He believed that technology could change. Also, he placed his faith in social institutions such as marriage. He believed that if fathers incurred the cost of bearing children there would be less children overall. If fathers considered how much children cost and whether they could afford children with their present occupation they would delay marriage. He called this "prudential restraint".

He did not talk with much reference to the environment as many other Neo-Malthusians have discussed. We will talk about these views in Part II and the views of the Neo-Institutionalists.

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