DSS sites in the INDEPTH Network have shown that principal components analysis of household assets and housing characteristics provide a basis to assign a socio-economic score to households that acts as a good proxy of income expenditure.  Assigning populations to wealth quintiles based on household wealth ranking has been shown by INDEPTH to allow powerful inequality and equity analyses of health outcomes and access to health services which have important gradients even within the apparently homogeneous populations in small demographic surveillance areas.  See the INDEPTH publication: Measuring Health Equity in Small Areas. INDEPTH.  Ashgate Publishing Ltd. Aldershot, UK

A sample asset survey questionnaire can be found in this link.

For cross site analyses of equity data from INDEPTH DSS sites, INDEPTH has prepared the following document: INDEPTH SES Standard Variables and Coding for Cross-Site Equity Analyses.pdf

See also: Stata PCA Routine for Asset Indexing