There are many countries around the world where the numerical value of the currency is so high that even the smallest purchases are calculated in thousands. To be a millionaire may mean having less than the equivalent of USD100 in your pocket. While official inflation may be low, unofficial inflation, from rounding up or, even, simply inflating unpublished prices, can have a startling effect on costs. And, of course, in environments where cash is the normal means of settlement, creates a profit that is secret from victims and, even, from employers and Revenue officials. But countries are reluctant to redefine their currencies. Why?