GNP measures the output of the country’s residents, regardless of where the main economic activity is actually carried out.
Income from foreign investment of residents of the country is included in the GNP, and foreign investment within the country is not. This is different from GDP, which measures output and income based on location rather than nationality.
GNP and GDP can have different values, and a large difference between a country’s GNP and GDP may indicate significant integration into the world economy.