In the 1990’s, none of C or I or G went down.
REvenue fraction of GDP went up because of clinton’s tax increases as well as income growth in more highly taxed sectors.
If the USA can get back to late 1990’s revenue share of GDP, it just about looks sustainable.
That is living in a world that doesn’t exist.
1990s numbers had easy North Sea oil flowing. Alaska is dying, too. And much of many places. Only difficult oil (difficult in joules in per joule out) flows now.
1990s numbers were pre dot com crash. Pre 9/11/2001. Pre 2008 Apocalypse and pre 2020 global plague. Each catastrophe was bailed out with interest generating debt. That world is gone and lost forever.
Dreadful sorrow, Clementine.
I say that it is possible, not that it is likely.
Oil sand production in Venezuala and Alberta would be profitable at much less than $80 a barrel.
Current oil prices are a political construct, not a constraint of nature.