"Deflation" is a common word but its meaning varies depending on the speaker. For instance, some use this word to mean a decline in consumer prices, whereas others use it to mean a decline in asset prices and in economic activity.
Moreover, the price indicator  BIS Review 132/2009  5  they refer to varies and there is no consensus view about the degree and duration of a price fall to determine "deflation." Regardless of the definition of "deflation," a matter of great importance is whether there are prospects for the economy to return to a sustainable growth path with price stability.