... governments often own productive businesses such as railways, postal services or energy providers. But, by accounting convention, state-owned enterprises that sell products at market prices are counted as private enterprises in the value added of the relevant sector: public railways are part of the transport sector, not the government sector. Even though state-owned corporations earn profits (and in the stats, higher profits means higher value added), their profits are accounted for in the industrial sector they work for, not the 'government' sector. So if the state-owned railway makes huge sales and profits (high value added), it boosts the transport sector value added, even if that sector is perhaps only successful because of state ownership. Only government-owned entities that don't sell at market prices are by definition included in the government sector. In short, from the perspective of national accounting, you don't count as government if you are doing market production. So, in the case of free public education, while increasing the number of teachers might add to GDP (because they are paid), the value they actually produce does not increase GDP. All of which means that government can only increase its value added with non-market production, thereby obscuring the true importance of government in the economy: value that government businesses do add is not shown in official statistics, nor is the value that education or health generate. These rules have been made in order to find a straightforward way to account for economic activity. Yet, when you consider the combined weaknesses of accounting conventions - government is lumped with households as a 'final' consumer; government cannot make a surplus, earn returns, increase its productivity or raise value added through market production - you can't help but notice that, while every effort has been made to depict finance as productive, the opposite seems to be true for government. Simply because of the way that productivity is defined, the fact that government expenditure is higher than value added reinforces the widely held idea that 'unproductive' government has to take before it can spend. This thinking by definition restricts how much government can influence the course of the economy. It underpins the theory of austerity. And it is a consequence of fables about government told over several centuries.
Mariana Mazzucato, The Value of Everything: Making and Taking in the Global Economy












