Radioactive money
The idea of 'expiring' money was suggested as an alternative to all the quantitative easing malarkey. Instead of giving money to banks to stash in the Cayman Islands, you give money to pensioners, with the proviso that it can't be saved, it has to be spent or you lose it. So they spend on shiny things, and people who make shiny things don't go bankrupt. The money will, of course, still eventually find its way to the Cayman Islands, but it hopefully will have done some good on the way.