Government predicts 40% fall in UK housing market, is this a self fulfilling prophesy?

.. surely if they start bandying these figures about, buyers will sit back and wait to see such a decline, but before you start saying it's great news for first time buyers.. consider all the hardship of negative equity, not to mention the knock-on effect on the general economy and not least of all, the fact that the banks are making mortgages as scarce as hen's teeth...