Preston curve

Preston Curve

The Preston Curve is a graphical representation that illustrates the relationship between life expectancy and real per capita income. Named after Samuel H. Preston, an American economist and demographer who first presented the concept in 1975, the curve demonstrates that wealthier countries tend to have higher life expectancy rates. However, it also shows diminishing returns in life expectancy gains with increasing wealth.

Overview

The Preston Curve plots the life expectancy of populations against their gross domestic product (GDP) per capita on a logarithmic scale. The general upward slope of the curve indicates that, on average, populations living in countries with higher incomes enjoy longer lives. This relationship, while robust across many nations and time periods, is not without exceptions and variations. Factors such as healthcare quality, education, and distribution of wealth also play critical roles in determining life expectancy, beyond the influence of average income levels.

Historical Context

Samuel Preston published his seminal paper, "The Changing Relation between Mortality and Level of Economic Development" in 1975, which introduced the Preston Curve. His analysis was groundbreaking, as it challenged the prevailing thought that improvements in health and life expectancy were solely the result of advancements in medical technology. Instead, Preston suggested that economic development was a crucial determinant of population health.

Implications

The Preston Curve has significant implications for public policy and economic development strategies. It suggests that policies aimed at economic growth could potentially lead to improvements in population health and longevity. However, the curve also highlights the importance of equitable growth and the distribution of wealth, as countries with similar income levels can have different life expectancies based on how wealth is distributed among their populations.

Criticism and Debate

Critics of the Preston Curve argue that it oversimplifies the relationship between income and health by not accounting for the myriad of other factors that influence life expectancy. These include genetic predispositions, lifestyle choices, environmental conditions, and the quality of healthcare systems. Additionally, some scholars point out that the relationship between income and life expectancy can vary significantly over time and between different regions, suggesting that the curve may not be universally applicable.

See Also

• Demography
• Economic development
• Health economics
• Life expectancy
• Gross domestic product