๐ The Ruler Analogy: Using GDP alone to measure development is like using height to measure a person's health. It tells you something useful โ but misses life expectancy, diet, fitness, mental health, and social connections. The HDI is like a more complete health check โ combining income, education, and life expectancy into one index.
Human Development Index (HDI):
HDI = Geometric mean of three normalised indices:
1. Life Expectancy Index (health)
2. Education Index (mean years + expected years of schooling)
3. GNI per capita Index (standard of living, PPP-adjusted)
Score: 0 (lowest) โ 1 (highest). Above 0.8 = Very High Development.
HDI = Geometric mean of three normalised indices:
1. Life Expectancy Index (health)
2. Education Index (mean years + expected years of schooling)
3. GNI per capita Index (standard of living, PPP-adjusted)
Score: 0 (lowest) โ 1 (highest). Above 0.8 = Very High Development.
๐ฉบ Health
Life expectancy at birth reflects nutrition, healthcare access, sanitation, and disease burden. A nation of wealthy but unhealthy people is not truly developed.
๐ Education
Literacy, school enrolment, and quality of education build human capital โ the foundation of long-run productive capacity and individual empowerment.
๐ต Income
GNI per capita (not GDP) includes income from abroad. PPP-adjusted to account for cost of living differences between countries.
โ๏ธ Inequality
The Gini coefficient measures income distribution. High HDI + high Gini = rich country with serious inequality (e.g., USA vs Scandinavia).