I=PAT

Doucet 2010

I = PAT Paper

The I =PAT formula seeks to identify the impact (I) human population (P), affluence (A), and technology (T) has on the environment (Dietz and Rosa, 1994). Hynes (1994) believes the appeal of using I=PAT to discuss environmental issues is the simplistic physical insight it provides. Traditionally, the (P) variable denoted the most importance, but trends in developed countries such as Canada, are causing widespread critique of the importance placed on population (Sherbinin, Carr, Cassels, & Jiang, 2007). Many believe technology is responsible for the greatest impact in developed countries (Commoner, 1972). Nonetheless, the single most important variable impacting the Canadian environment is the population (P) because its great influence of and interaction with variables (A) and (T). First, Canada’s promising land allowed early habitants to develop affluence and technology. However, the impact of an increasing population, coupled with abundant natural resources enabled and pressured the Canadian economy to grow. Second as the economy matured, the population grew more, the more the demand for consumption grew, and the more waste accumulated. Third, in the relationship I = PAT, the impact of (P) can explain the changes in the growth of (A) and (T). The size of (P) affects the affluence in the economy, which in turn affects the amount of capital used to develop new technology.

The debate

One of the most important arguments regarding I=PAT is determining the variable that impacts the environment the most. Many refute the theory that (P) is the most important variable as developing countries with very large populations have smaller impacts on the environment than developed countries with relatively smaller populations (Commoner, 1972). Commoner (1972) argues that technology is the culprit as evident by the fast growing pace of technology and the stable growth of the population in developed countries. However, each of the variables holds different levels of importance in different environments and economies. Canada’s environment is ideal for a growing economy. Canada’s rich natural resources have made it possible for individuals to flourish and for the economy to grow. The country’s natural resources have made economic profits and investments in technology possible. In early history, many migrants were attracted to Canada for its rich land. Affluence and technology did not take precedent until the population grew denser. Larger communities required greater affluence and efficient technology to support the population. Thus, although the impact from technology is growing faster than affluence or population, it is driven by needs of the population. A massive reduction in the population level would inevitably curb the need for innovative technology, and decrease production as consumption would also decrease.

The impact of (P)

Evidence to support the debate of population’s impact is seen even when measuring the (P) variable independently, one can denote that a greater population can have a greater impact on the environment. “All people use resources and create waste, and many people have children who use more resources and create more waste” (Hynes, 1994, p. 19). In 2006 Canada’s population rate alone had almost doubled since 1956 (Statistics Canada, 2008). As the population in Canada has grown so has the amount of CO2 emissions, pollution, and the loss of wildlife habitats (Statistics Canada, 2008). However, the greater impact of Canadian’s on the environment is not attributed solely to an increase in population. This is evident when looking at the rates of growth of both the population and impact on the environment. As noted by Statistics Canada (2008) “ Population growth is an important piece of the puzzle for understanding our impact on the environment; however, it must be considered in conjunction with the other pieces” (Para 19).

The impact of (P) in conjunction with (A) and (T)

Although the size of the population is an important variable in measuring society’s impact, there are two other variables that interact with (P) to determine the full impact on the environment. Those variables are affluence (A) and technology (T). Variable (A) is measured by GDP or per capita consumption, and (T) expresses the amount of technology used to supply units of consumption (Gretchen, Daily, & Ehrlich, 1992, Para 10). Therefore, the total affluence and technology used in the Canadian economy also impact the environment. The consumption function of an economy is not based on population alone, but on marginal propensity to consume, which is based on income. Wealth is an important component as it drives an economy’s GDP (A). The more wealth there is, the more consumption, and waste (Dornbusch, 2005). The same holds true for technology as it increases the productive capacity of the economy (Gretchen, et al., 1992). Statistics Canada (2008) reported that the national growth in automobiles outpaced the growth in population during the late 50s, 60s, and 70s. The growth rate in consumption can be attributed to increases in affluence and technology. Dornbusch (2005) states that GDP is a measure of aggregate demand. There are three ways GDP can grow. The first is an increase in the population and pressure for more goods to sustain the population. The second is increased demand for goods from a larger propensity to consume because and the wealth effect. Last, a greater propensity to consume and economies of scale reduce prices. Although (A) and (T) are measured independently, an increase in population not only increases the multiplier effect but it can also increase each variable.[1] To grow GDP, production needs to increase, which entails more inputs such as labor (Dornbusch, 2005). The relationship between labor and capital demonstrate that a larger population increases GDP or affluence (A). GDP increases wealth, and new technologies are developed due to economies of scale. Nonetheless, although affluence and technology greatly impact the environment, their interaction with population produces the greatest impact.

Conclusion

I=PAT, although simplistic, allows individuals to measure the impact interactions between population, affluence, and technology have on the environment. Critics argue that technology in developed countries is the culprit. But strong evidence suggests that population is responsible for the greatest impact in the Canadian environment. It is not population alone or the figure represented by the variable that measures the full impact. Rather, the full impact is measured by the role it plays on the growth rate of affluence and technology.

 

 

 

 

 

 

 

 

 

 

 

 

References

Commoner, B. (1972). The environmental cost of economic development. In Population resources and the Environment. Washington, DC: Government Printing Office.

Dietz, T. & Rosa , E.A. (1994). Rethinking the environmental impacts of Population, Affluence and Technology. Human Ecology Review. Summer/Autumn, (1).

Dornbusch, R., (2005). Macroeconomics (7^th ed.). Canada: McGraw-Hill Ryerson.

Gretchen, C., Daily, & Ehrlich, P.R., (1992). Population, sustainability, and earth’s carrying capacity: a framework for estimating population sizes and lifestyles that could be sustained without undermining future generations. American Institute of Biological Sciences. Retrieved on October 14^th from: http://dieoff.org

Hynes, H. (1994). Taking population out of the equation: Reformulating I=PAT. Women’s International Network News, 20(4), 19. Retrieved from MasterFILE Premier database.

Sherbinin, A., Carr, D., Cassels, S., & Jiang, L. (2007). Population and environment. Annual Review of Environment and Resources (32), 345-373. Retrieved from: www.anualreviews.org

Statistics Canada (2008). Canada’s growing population and its environmental influence, 1956 to 2006. Retrieved on October 15, 2010 from: http://www.statcan.gc.ca

 

 

 

 

 

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[1] When (P) increases the value of P creates a multiplier effect on (I) as the greater value is not added to (A) and (T) but multiplied. I = (P) x (A) x (T). However, and increase in (P) can lead to an increase in (A) and (T) as these figures are calculated on a per capita basis. Therefore, (I) would derive from a multiplication of larger (P), (A), and (T) variables.