The key question: where does government get the money that it spends to support economic growth. From Frank Shostak at mises.org:
According to many commentators, outlays by government play an important role in the economic growth. In particular, when an economy falls into a slower economic growth phase the increase in government outlays could provide the necessary boost to revive the economy so it is held.
The proponents for strong government outlays when an economy displays weakness hold that the stronger outlays by the government will strengthen the spending flow and this in turn will strengthen the economy.
In this way of thinking, spending by one individual becomes part of the earnings of another individual, and spending by another individual becomes part of the first individual’s earnings.
So if for some reason people have become less confident about the future and have decided to reduce their spending this is going to weaken the flow of spending. Once an individual spends less, this worsens the situation of some other individual, who in turn also cuts his spending.
Following this logic, in order to prevent an emerging slowdown in the economy’s growth rate from getting out of hand, the government should step in and lift its outlays thereby filling the shortfall in the private sector spending.
Once the flow of spending is re-established, things are back to normal, so it is held, and sound economic growth is re-established.
The view that an increase in government outlays can contribute to economic growth gives the impression that the government has at its disposal a stock of real savings that employed in emergency.
Once a recessionary threat alleviated, the government may reduce its support by cutting the supply of real savings to the economy. All this implies that the government somehow can generate real wealth and employ it when it sees necessary.
Given that, the government is not a wealth generator, whenever it raises the pace of its outlays it has to lift the pace of the wealth diversion from the wealth-generating private sector.