We use national account data without realizing the efforts that lie behind the construction of these account. And frankly, it is sometimes like sausage making, but less and less so as the United Nations have managed to enforce rather widely its standards. But getting to these standards has been a very process.
Frits Bos documents the history of national accounting over three centuries. He shows that significant efforts and advances in national accounting arouse from two kinds of needs: understanding recent major crises and the increase of influence of the state and its policy making. To fix an economy, you need to know what is wrong with it, or at least the symptoms. To set policy, one needs measures to establish goals and how they have been reached.