While I can't say that Musk is right, I also can't say he is completely wrong here.<p>The private sector can also spend on dumb and inefficient things and we are fine in counting it in the GDP metric, the difference between private sector and the government is the source of revenue. The private sector has to produce something for the economy before spending (it may be done indirectly through debt, but it's not important here), while the latter forces the economy to share it's productive capacity (using violence if necessary) while not producing anything itself (well, technically it does, but it's usually a tiny amount of the total revenue). It's still fine, since it's just a form of re-distribution from one private entities to others. It can be grossly inefficient, but so can be the private spending.<p>The problem is when a significant portion of the government revenue is fueled by debt which can not be paid by the future economy growth. The government quickly engineers negative real interest rates either by forcing commercial banks and pension funds to buy it with regulations, or by outright money printing, which is easy to do in a fiat system. Such debt-fueled GDP growth is not a sign of strength, but instead a sign of weakness, and ideally it should be heavily discounted.