Ronan Lyons reports some striking calculations on the potential extent of negative equity in Ireland. He estimates that as many as 340,000 homes may be in negative equity, which corresponds to about one home in five. These calculations raise a number of other important questions. What fraction of these loans may end up being defaulted on? And what are the likely losses for the banks? These losses have not been incorporated into any of the calculations relating to the loans going into NAMA, so these losses will be over and above any losses associated with NAMA transfers.