I have already explained why it is our conviction that limiting attention to an ex ante fixed horizon would be arbitrary and could induce sometimes short-sighted, sometimes delayed reactions. I should mention the recent tendency seen in some inflation-targeting central banks towards relaxing their emphasis on a fixed horizon, in favour of the more flexible medium-term notion.
Also, because of relatively richer data in terms of detail, time, reliability and industry-specific price indices, among others, much research has been devoted to scrutinizing manufacturing, while the rest of the economy has faced less examination in spite of the fact that major productivity problems lie outside manufacturing.