" who decides when the monetary base gets expanded and by how much" You allow entities to trade assets for currency at a central bank. The central bank can do

" who decides when the monetary base gets expanded and by how much" You allow entities to trade assets for currency at a central bank. The central bank can do it (i.e. Fed exchanging currency for TBills). The ECB allows banks to exchange assets (like property) for Euros. This is good because it allows flexibility in the amount of currency in circulation. Without this, you can get into all sorts of trouble, for example, Spain, Greece, et. al. in the 'Euro trap'. Monetary policy can be dangerous, of course, like anything powerful, but it can be used for good. Also to the commenters point about 'inflation is a tax' - well, it's a 'tax on cash' and a 'negative tax to everything else'. It's really nothing like a tax at all, it shouldn't be referred to as such. Inflation/deflation is just the changing value of one good vis-a-vis another. There are a lot of 'stores of value' out there and anyone with significant enough portfolio can easily take advantage of those if they chose for whatever reason not to hold a specific currency.