1. The Spatial GINI Coefficient
Dr. Paul C. Sutton
Department of Geography
University of Denver
Population Assocation of America Conference
San Francisco May 3rd, 2012

2. Outline
Lorenz Curve and the GINI Coefficient as a measure of distribution of wealth
Global gridded representations of Nighttime Satellite Imagery and Population Density as an alternative source for developing a spatially derived Lorenz Curve.
The Human Development Index (HDI)

3. Nighttime Lights of the World
Data Products Used
Nighttime Lights of the World
DMSP OLS (NGDC)
LandScan Global Grid of Population

4. Scatterplots of Light vs Population for Pixels in China (left) and U.S. (right)

5. The Spatial GINI Coefficient I

6. The Spatial GINI Coefficient II (also referred to as the “Lumen GINI”)

7. The “Real” Income GINI Coefficient
Note: Research suggests the United States is on track to pass Mexico

8. Highly variable ‘freshness’ of Data
Due to the lack of a systematic international data collection system, the data used to calculate income Gini coefficients span nearly two decades

9. The Global Spatial GINI
The Lorenz curve for the global Lumen Gini Coefficient, formed by combining the data from all countries.

10. Lorenz curves and Lumen Gini coefficients for six countries

11. Map of national Spatial GINI Coefficients

12. Map of Subnational Spatial GINI Coefficients

13. Map of Spatial GINI Coefficients at a 0.25 degree grid

14. Spatial GINI vs. Income GINI
National level Lumen Gini versus Income Gini coefficients. Note the poor correlation, indicating that the two Gini’s are measuring very different phenomena.

15. Spatial GINI vs Per Capita Energy Consumption and Electrification Rates

16. Spatial GINI vs. Human Development Index

17. Spatial GINI vs. Human Security Index

18. Spatial GINI vs. Ecological Footprint

19. Discussion & Conclusions
The Spatial GINI or Lumen GINI does not measure
distribution of wealth in any manner similar to the
Income GINI.
The Spatial GINI correlates strongly and significantly
with both the Human Development Index (HDI) and
The Human Security Index (HSI).
Simple, empirical measures such as the Spatial GINI
as presented here present an opportunity for improved
spatially explicit characterizations of the human
condition.