Professor Gregory Connor:

In an asset pricing bubble, particularly on the mortgage side more than on the property development side, especially in investment mortgages, people were interested in flipping properties, that is, buying a property not because they had a long-term interest in holding it for rental but to flip it quickly within a few years for a profit. This worked for several years in a row. That is common in asset pricing bubbles - that people buy a property not for its intrinsic value but the fact that they can sell it on in what is sometimes called "the greater fool problem". You think you can buy a property, even though it is overvalued, because you can sell it to someone who will pay even more. There was some of this. As the debt capital inflow into the Irish banks manifested itself in excessive of mortgage lending, that pushed up prices properties. The banks then encouraged speculative investors to buy properties in order to flip them. It was obviously a Ponzi scheme which could not go on forever.