Per-capita gross domestic product (GDP) is often used as a proxy for measures of standard of living or quality of life.
Montgomery et al. examine several proxies used, and point out limitations with each, stating "In poor countries, no single empirical measure can be expected to display all of the facets of the concept of income.
Our judgment is that consumption per adult is the best measure among those collected in cross-sectional surveys.
"[2] Frost lists several examples of proxy variables:[3]
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