Inequality is usually regarded as an ethical issue. This article attem
pts to show that inequality also has a central role to play in the wor
kings of the economy. Economic theories have not given sufficient atte
ntion to this view of the problem, and this is why they cannot account
for situations of social instability. Economic equilibrium has been i
dentified as being the same thing as social equilibrium. This article
presents the central features of an economic theory of social equilibr
ium based on the theory of distributive equilibrium. The situation in
Latin America in the 1980s and 1990s is used to test the validity of s
uch a theory. The observed decline in private investment, combined wit
h a drastic fall in real wages in an environment of social violence in
the region, is consistent with the predictions stemming from this the
ory. A society in which there is excessive inequality is an unstable s
ociety. It cannot experience sustained growth or aspire to being fully
democratic.