Per capita income (PCI) or average income measures the average income earned per person in a given area (city, region, country, etc.) in a specified year. In many countries, per capita income is determined using regular population surveys, such as the American Community Survey. This allows the calculation of per capita income for both the country as a whole and specific regions or demographic groups. However, comparing per capita income across different countries is often difficult, since methodologies, definitions and data quality can vary greatly. Since the 1990s, the OECD has conducted regular surveys among its 38 member countries using a standardized methodology and set of questions. Per capita income is often used to measure a sector's average income and compare the wealth of different populations. Per capita income is also often used to measure a country's standard of living. When used to compare income levels of different countries, it is usually expressed using a commonly used international currency, such as the euro or United States dollar. It is one of the three components of the Human Development Index of a country.

Limitations

While per capita income can be useful for many economic studies, it is important to keep in mind its limitations.