Scarred by the recent Irish economic crash, some observers feel an anxious sense of déjà vu when they hear predictions of rapid dairy growth in Ireland. They worry that it is another case of “irrational exhuberance”, the infamous phrase uttered by US Federal Reserve chair Alan Greenspan in relation to the “dot.com” asset price bubble.My response to that is, no, it is not a mirage built on an imaginary market, but neither is it a one-way bet without risk. There will be periods of extreme volatility and there will be casualties. As has happened in the Irish pig sector, only the fittest will survive.