Font size:
Print
Preston Curve
Preston Curve
- It posits an empirical relationship between life expectancy and per capita income in a country.
- It suggests that as per capita income increases, so does life expectancy.
- The concept was first proposed by American sociologist Samuel H. Preston.
Trends in the Preston Curve:
- Initial Growth: When a poor country experiences economic growth, its per capita income rises, leading to a rise in life expectancy initially.
- This rise is attributed to improved access to healthcare, education, nutrition, and cleaner surroundings.
- For example, the average per capita income in India increased from ₹9,000 per year in 1947 to around ₹55,000 per year in 2011, correlating with an increase in life expectancy from 32 to over 66 years during the same period.
- This rise is attributed to improved access to healthcare, education, nutrition, and cleaner surroundings.
- Flattening Effect: The positive relationship between per capita income and life expectancy begins to flatten out after a certain point.
- Beyond this threshold, further increases in per capita income do not result in rises in life expectancy.
- This suggests that human lifespan may have limitations.
Issues with the Preston Curve:
- Causal Relationship:
- Some economists argue that economic growth is the key to improving development outcomes, citing examples like India and China.
- Others contend that improvements in life expectancy at low income levels are due to advancements in medical technology.
- Thus, emphasis should be on public investment in human development.
- Technological Advancement:
- Critics of the technology-focused view argue that technological progress is closely linked to income levels.
- However, poor countries can benefit from technology transfers from wealthier nations.
- This enables them to achieve higher life expectancy despite low income levels.
- Historical Context:
- Today, poor countries may enjoy higher life expectancies than in the past due to medical technology advancements from wealthier nations.
- This phenomenon highlights the importance of technology transfers in improving development indicators.