The U.S. $10,000 was available till Nixon nixed it in 1969 For the last few years the conversation about cash has been dominated by Ken Rogoff's proposal to remove high-denomination banknotes. In an effort to broaden the discussion, last year I wrote an essay for Cato Unbound about introducing a new U.S. supernote. The value of the current highest denomination note--the $100 bill--has deteriorated over the decades thanks to inflation. Is it time to restore the purchasing power of U.S. cash by bringing out a $1,000 note? In the same essay I also floated the idea of taxing the supernote. Why a tax? A new $1,000 bill could be used for both good and nefarious purposes. Given that nefarious supernote usage (tax evasion and crime) could impose costs on society, a tax would make up for this by transferring wealth from note users to the rest of us. (I also blogged about the idea of taxing cash here and here ). Josh Hendrickson, Will Luther, and Jamie McAndrews all had responses. Do rea...