The Preston curve, proposed by Samuel H. Preston in 1975, delineates a relationship between life expectancy and per capita income in countries. It highlights that as per capita income rises, so does life expectancy, albeit with diminishing returns.
Initial Observations:
- Preston observed that wealthier countries generally exhibit longer life spans compared to poorer countries.
- Factors contributing to this phenomenon include better access to healthcare, education, cleaner environments, and improved nutrition.
Impact of Economic Growth:
- Initial stages of economic growth in a country lead to a significant increase in life expectancy due to improved living standards, healthcare, and nutrition.
- Example: India witnessed a rise in per capita income from ₹9,000 in 1947 to ₹55,000 in 2011, accompanied by an increase in life expectancy from 32 years to over 66 years.
Diminishing Returns:
- The positive correlation between per capita income and life expectancy eventually flattens out.
- Beyond a certain point, further increases in per capita income do not substantially enhance life expectancy.
Broad Applicability:
- The Preston curve’s principles extend beyond life expectancy to other development indicators such as infant and maternal mortality, education, and healthcare.
- Higher per capita income correlates with improvements in these indicators.
Debates on Causality:
- Economists differ on whether economic growth directly causes improvements in development indicators.
- Some argue that economic growth drives development outcomes, citing examples like India and China.
- Others contend that improvements in life expectancy, especially at lower income levels, stem from public investments in healthcare and technology.
Influence of Technology:
- Technological advancements play a crucial role in improving life expectancy and development indicators.
- Poor countries can benefit from technology transfers from richer nations, thereby improving their development outcomes despite low income levels.
- Critics argue that technological advancement itself is linked to income levels, giving richer countries an initial advantage.
Multiple Choice Questions (MCQs):
- Who proposed the Preston curve?
- A) Samuel H. Preston
- B) Adam Smith
- C) Karl Marx
- D) John Maynard Keynes
- Answer: A) Samuel H. Preston
- What is the relationship between per capita income and life expectancy according to the Preston curve?
- A) Negative correlation
- B) Positive correlation with diminishing returns
- C) No correlation
- D) Inverse correlation
- Answer: B) Positive correlation with diminishing returns
- What factors contribute to the initial increase in life expectancy during economic growth, as per the Preston curve?
- A) Better access to healthcare and education
- B) Increased pollution
- C) Lack of clean water
- D) Decreased nutrition
- Answer: A) Better access to healthcare and education
- Beyond what point does the positive relationship between per capita income and life expectancy begin to flatten out?
- A) After a country achieves middle-income status
- B) After a country becomes a high-income nation
- C) After a country’s per capita income reaches a certain threshold
- D) After a country’s per capita income surpasses $100,000
- Answer: C) After a country’s per capita income reaches a certain threshold
- Which viewpoint regarding the Preston curve emphasizes the role of public investment in healthcare and technology?
- A) Economic growth drives development outcomes
- B) Technological advancement is linked to income levels
- C) Improvement in life expectancy occurs due to a shift in the curve
- D) Higher life expectancy is achieved through technology transfers
- Answer: C) Improvement in life expectancy occurs due to a shift in the curve