Global Consumption from the Perspective of Population Health
Hertzman, Clyde, Journal of Business Administration and Policy Analysis
Can wealthy societies maintain their health status while consuming less of the world's "photosynthetic resources"? This may seem like an esoteric question, yet Canada has recently ratified the Kyoto Accord. In order to meet its commitments under the Accord, Canada will need to reduce emissions of carbon dioxide by approximately 20% over the next decade. Since carbon dioxide is the end product of consumption of "photosynthetic resources" the question is de facto irresistible.
In the modern world, health, wealth, and consumption tend to occur together. Increasing per capita income among countries tends to be associated with increasing longevity. Early in this century the relationship was simple: life expectancy was longer in countries with higher per capita incomes. However, in recent decades the relationship between health and wealth has become more complex as rich nations have grown richer. The specific character of this complexity forms a basis for a more encouraging answer to the question posed above.
When longevity and national income curves are plotted together on a single graph, the cause for optimism can be seen in the changing character of the curves throughout the twentieth century. Figure 1 shows that, in 1900, the relationship between increasing national health and wealth was nearly linear. Wealthier meant healthier. But throughout the twentieth century the strength of this association increasingly broke down. By 1960, the slope of the health-wealth curve had flattened at the "rich end," such that variations in national income per capita were no longer strongly associated with further increases in life expectancy. By 1990 all the world's wealthiest nations (those belonging to the Organization of Economic Cooperation and Development) found themselves on this "flat of the curve" (World Bank 1993). At the same time, the traditional monotonic relationship between health and wealth persisted among the world's poorer countries; a pattern referred to here as the "steep incline", to distinguish it from the "flat of the curve".
[FIGURE 1 OMITTED]
There are several ways to interpret these trends. One of the simplest is to assert that the material factors that limit health status in poor societies, such as food, clothing, shelter and clean water, become relatively unimportant determinants of health when national income reaches a certain level. This is intuitively appealing because there is such a thing as a sufficient amount of food, clothing, shelter, and clean water, beyond which further consumption should not lead to further health benefit. It may be pleasant to have better food, clothing and shelter, but they would not necessarily confer additional health benefits.
One simple conclusion, from the standpoint of economic development and health, is that poorer countries' attempting to match the rich, and reach the flat of the curve, is an essentially benign objective. In other words, the relationship between healthy and wealthy countries and poor and unhealthy countries ought to be one of imitation of the former by the latter. This interpretation assumes that economic growth, traditionally defined, is a laudable objective regardless of the forms that it takes. But this view is challenged by evidence that shows how differently rich and poor nations appropriate global photosynthetic resources. This is best represented in the calculation of the "ecological footprint", which is a measure of the area of the Earth's surface appropriated for its use by a given population in a given year (Wackernagel 1995).
Consumption of ecologically productive land (that is, land appropriated for energy, agriculture, and forest products as well as the area of the built environment per se) has grown rapidly across the globe in recent decades. Between 1950 and 1990, the appropriation of ecologically productive land by the worlds' richest countries increased from approximately 2 hectares to between 4 and 6 hectares per capita. …