The financial system mathematically requires there to always be more money printed next year than this year, or the system implodes.
Printing is not the primary mechanism that causes the money supply to be inherently inflationary: debt and interest is the real byproduct of monetaryism. Inflation by Excessive Money Printing is not what requires central banks to print more money in order to prevent implosion. It's that because money is created out of debt, interest is what causes the money supply to expand making monetary expansion a necessity. Your knowledge of macro is probably not from studying econ. The first 20 minutes of Zeitgeist II: Addendum will explain this in a more entertaining way than reading the writings of a boring quantitative financial analyst. <iframe width="420" height="315" src="http://www.youtube.com/embed/1gKX9TWRyfs" frameborder="0" allowfullscreen></iframe>