Illustration of Simpson's Paradox for the unemployment / ethnicity relationship.

    Employed Unemployed Total
Zone A      
  White 81 9 90
  Asian 9 1 10
  Total 90 10 100
Zone B      
  White 40 10 50
  Asian 40 10 50
  Total 80 20 100
TOTAL      
  White 121 19 140
  Asian 49 11 60
  Total 170 30 200

 

 

 

 

 

 

 

 

It appears, in aggregate, that the Asian unemployment rate is 18% while the White unemployment rate is only 14%, yet we know that the two groups have identical unemployment rates in Zone A and Zone B.

Table taken from Table 3.6, page 50, of Green, M. and Flowerdew, R. 1996. New evidence on the modifiable areal unit problem. Page 41-54 in P. Longley and M. Batty (eds) Spatial analysis: modelling in a GIS environment. Cambridge: GeoInformation International.