The Malthusian Paradox: Declining Food Prices in the Very Long Run

More than two centuries ago in his Essay on the Principle of Population, Thomas Malthus famously issued his dire prediction that mankind was doomed to survival at a subsistence level. His concept of population growth expanding to absorb the available food supply has been roundly contradicted by history, thanks in part to a declining birth rate in rich countries. However, economics is still the “dismal science”, as the underlying idea of natural resource scarcity impinging on the prospects for progress remains a cornerstone of modern economics. In the case of agriculture, the proposition is that more people or richer people increase the demand for food and given the constraint on arable land, this means that food becomes scarce. In economics, price is taken as the paramount indicator of scarcity. Yet, as we demonstrate with data stretching back to 1650, real prices of most food products, the price of food relative to those of other goods, have fallen dramatically. For example, in 2008 the real price of wheat was only 4% of its 1650 level, while corresponding ratio for the price of sugar was less than 0.05%. There are exceptions to the dominance of declining trend, particularly meat products in recent centuries, but for most periods and most products the trend is distinctly towards lower prices. What is missing in the “dismal science” that explains the failure of the Malthusian prediction? We follow the suggestion in Schumpeter’s The Theory of Economic Development that the answer lies in understanding the process of economic development. In particular, he contrasts the analysis of economic development to that of the equilibrium analysis of a stationary state implicit in the analysis of Malthus and other classical economists. This implies technical change is assured under capitalism, but it is discontinuous and its nature, location and extent are uncertain. We argue that this implies all inputs to production are subject to augmentation in their productivity, natural resources no less than capital or labour. The tendency toward declining real prices of food products can then be taken as evidence that technological change has augmented the productivity of land in food production to a greater extent than the average augmentation of all inputs utilised in production finished goods generally.