Dr. Ronan Lyons:

I do, indeed. In my original submission I gave this picture of the wealthiest and the least wealthy households. No matter what one does, if one picks a minimum deposit of 10% or 20%, one is effectively drawing a line and saying that at some point the people below the line will not be able to buy a property. The reason one would set the line at anything other than at the lowest point possible, is for the reason of financial stability, because of the families in negative equity. As soon as one puts it above the minimum possible, one needs to have a well thought out social housing strategy to provide long-term accommodation. That is not to say there are no other tools.

I think a deposit of 20% is the correct way to go, but not overnight. If one gave me a few pints and twisted my arm, I could be haggled down to 15% - a terrible way to decide macro prudential policy.