THE GOVERNED ECONOMY
The governed economy contains central authorities often simply called "the government" - who levy taxes on firms and households and which engages in numerous activities such as defending the country, making and enforcing the laws, building roads, running schools, and predicting weather.
When the government produces goods and services that households desire such as roads and air traffic control, it is obviously engaged in a useful activity and is obviously adding to the sum total of valuable output. The National Income Statistician count as part of the GNP every government expenditure on goods and services, whether it is to build a scud missile to promote police protection, or to pay a civil servant to file and re-file papers from a now defunct ministry.