Another reason is that factors that exerted strong downward pressure on wages and prices during the deflation period, especially in the mid-2000s, such as the increase in non-regular workers and inflows of low-priced imports from emerging economies, are unlikely to put further downward pressure on wages and prices.
Yet another reason is that, under QQE, inflation expectations seem to have risen and the Phillips curve has started to drift upward. This is confirmed, as mentioned earlier, by developments in inflation expectations gauged through various surveys and market indicators as well as recent patterns in wage and price setting. It is difficult to clearly disentangle the contributions of these different factors.