The 1995 British two pound "Dove" coin The Bank of England's chief economist Andrew Haldane recently called for central banks to think more imaginatively about how to deal with the technological constraint imposed by the zero lower bound on interest rates. Haldane says that the lower bound isn't a passing problem. Rather, there is a growing probability that when policy makers need three percentage points of headroom to cushion the effects of a typical recession, that headroom just won't be there. Haldane pans higher inflation targets and further quantitative easing as ways to slacken the bound, preferring to focus on negative interest rates on paper currency, a topic which gets discussed often on this blog. He mentions the classic Silvio Gesell stamp tax (which I discussed here ), an all out ban on cash as advocated by Ken Rogoff, and Miles Kimball's crawling peg (see here ). According to Haldane, the problem with Gesell's tax, Rogoff's ban ( pdf ), a...