Income distribution and mortality in Sweden

Abstract

Background: The hypothesis that a high income inequality on a societal level is associated with poor health
outcomes has been both rejected and accepted in empirical studies. Whether the influence of economic
circumstances on health operates at the individual level or societal level has important implications on policy
and intervention alternatives. The objective of this study was to analyse the relationship between income
inequality and mortality in Swedish municipalities and if the relationship varies depending on the mean
income or on the time-lag between income inequality and mortality.
Methods: The study was based on register data on mean income and income inequality (Gini coefficients)
from Statistics Sweden 1982 and 1998, aggregated on the municipality level. Data on age-standardised death
rates per 100,000 persons were obtained for 1983, 1988, 1993, 1998 and 2002. The analysis on 1998 was a
test of the robustness of the results.
Results: The relationship between high income inequality in 1982 and mortality in 1983 was negative with a
similar relationship in 1998. Using latency periods, the results show a decreasing trend of mortality in relation
to higher Gini coefficients. A positive relationship between Gini and mean income implies that municipalities
with larger income distribution also had a higher mean income and vice versa.
Conclusions: High income inequality does not have a negative effect on mortality in Swedish municipalities.
The municipalities with high income inequality have also high mean income as opposed to many other
countries. The income level seems to be more substantial for mortality than the income inequality.