Preston Curve

Source – This post on Preston Curve has been created based on the article “What does the Preston curve postulate?” published in “The Hindu” on 4 June 2024.

Why in News?

It has been observed that with the increasing per capita income in India, there has been a shift in attention towards Preston curve which was first proposed by “Samuel H. Preston” in the year “1975“.

About the Preston Curve

1. About: The Preston Curve is a graph that shows the relationship between the average income per person in a country (usually measured as GDP per capita) and the average life expectancy of its people.

2. Origin: The concept was introduced by American sociologist Samuel H. Preston in his 1975 paper titled “The changing relation between mortality and level of economic development”.

3. Key Observations of the Preston Curve:

i) Generally, people in wealthier countries live longer compared to those in poorer countries.

ii) This trend is likely because individuals in richer nations typically have better access to healthcare, education, clean environments, and nutritious food.

iii) Economic Growth and Life Expectancy: When a country’s economy grows and incomes rise, life expectancy also tends to increase significantly. This improvement is initially due to better access to basic necessities like food and healthcare.

Example: In India, the average income rose from approximately ₹9,000 per year in 1947 to about ₹55,000 in 2011. Correspondingly, the average life expectancy increased from 32 years to over 66 years during the same period.

5. Limitations of Income Growth on Life Expectancy: The relationship between per capita income and life expectancy starts to plateau beyond a certain point. Further increases in income do not lead to significant gains in life expectancy, possibly because there is a natural limit to human lifespan.

UPSC Syllabus: Economy