Can we explain what determines inflation yet?

Previously, we had a quite simple theory on inflation. This theory has the following characteristics: In the short term there is a Phillips curve, and inflation is a result of the fall in the unemployment rate; In the long term, inflation is determined by money supply growth, by monetary policy. But we are currently seeing, worldwide or in OECD countries, that the short-term correlation between inflation and unemployment rate has disappeared, and so has the long-term correlation between inflation and money supply growth. So what is the mechanism that determines inflation? There are not very many possible explanations: The neo-Fisherian explanation: inflation is determined by nominal interest rates chosen by central banks; The self-fulfilling expectations explanation: expected inflation determines wage increases and unit labour costs, which means that at equilibrium inflation will be identical to expected inflation. Several levels of inflation are then possible, for example if the indexation of wages to prices is better above a certain level of inflation. Inflation would then be a "convention" fluctuating over time.