(3) Per capita income of citizens Explanation: Gross National Product (GNP) is the market value of all products and services produced in one year by labour and property supplied by the residents of a country. Basically, GNP is the total value of all final goods and services produced within a nation in a particular year, plus income earned by its citizens (including income of those located abroad), minus income of non-residents located in that country. GNP measures the value of goods and services that the country's citizens produced regardless of their location.