In statistics

Statistics

Statistics is the study of the collection, organization, analysis, and interpretation of data. It deals with all aspects of this, including the planning of data collection in terms of the design of surveys and experiments....

, a proxy variable is something that is probably not in itself of any great interest, but from which a variable

Variable (mathematics)

In mathematics, a variable is a value that may change within the scope of a given problem or set of operations. In contrast, a constant is a value that remains unchanged, though often unknown or undetermined. The concepts of constants and variables are fundamental to many areas of mathematics and...

 of interest can be obtained. In order for this to be the case, the proxy variable must have a close correlation

Correlation

In statistics, dependence refers to any statistical relationship between two random variables or two sets of data. Correlation refers to any of a broad class of statistical relationships involving dependence....

, not necessarily linear or positive, with the inferred value.

Examples

Per-capita GDP is often used as a proxy for measures of standard of living

Standard of living

Standard of living is generally measured by standards such as real income per person and poverty rate. Other measures such as access and quality of health care, income growth inequality and educational standards are also used. Examples are access to certain goods , or measures of health such as...

 or quality of life

Quality of life

The term quality of life is used to evaluate the general well-being of individuals and societies. The term is used in a wide range of contexts, including the fields of international development, healthcare, and politics. Quality of life should not be confused with the concept of standard of...

.

Likewise, country of origin or birthplace might be used as a proxy for race.