The Preston Curve, first described in 1975, shows that people in richer countries tend to live longer — but the relationship is logarithmic, not linear. Initial gains in GDP dramatically improve life expectancy, but the effect plateaus. A country moving from $1,000 to $5,000 GDP/capita sees far greater health gains than one moving from $40,000 to $80,000.
GDP Per Capita (USD) vs Life Expectancy (Years)
213 countries with available data
Correlation (r)
0.609
Moderate positive
Countries
213
with both indicators
Avg GDP Per Capita
$23k
global average
Avg Life Expectancy
74 yr
global average
Key Insight
The data shows a strong logarithmic correlation — doubling GDP from low levels can add 10+ years of life expectancy, while doubling from high levels adds very little.
Regional Averages
| Region | Countries | Avg GDP Per Capita | Avg Life Expectancy |
|---|---|---|---|
| Africa | 54 | $3k | 65 yr |
| Asia | 48 | $17k | 75 yr |
| Europe | 47 | $51k | 80 yr |
| Americas | 45 | $25k | 76 yr |
| Oceania | 19 | $17k | 72 yr |