nearly zero
a zero sum resource is always conserved. ie new resources don't enter the game. neither do resources leave the game. the stanley cup is a zero sum resource. houses and corn are not. monopoly money is a zero sum resource if you include the bank. a game is zero sum game if all resources are zero sum. the us economy is definitely not a zero sum game. because it has resources like labor and lumber. real us fiat money is not a zero sum resource. but it's pretty close. it's a zero sum resource for everyone except the federal reserve and the us treasury. between them they create some $50 billion in a typical year. that sounds like a lot. but it's about 5% of the money in circulation. about half of it is absorbed by a growing economy. the other half shows up as inflation. so in one sense, inflation is a tax. heh.