Socio-economic indicators are useful for everything. Organizations and politicians can look at poverty, income and employment rates to make an analysis about development. Or someone studying why people smoke can use socio-economic indicators income, education and occupation to determine who is more likely to smoke.
Socio-economic indicators, which really can be any category describing the qualities of society, help us make correlations to understand cause and effect relationships.
Anyone here studying social sciences? I'm sure you know what I'm talking about.