Well, I thank Vikki Howells for that really interesting and important question. That now means, Llywydd, we've mentioned all four taxes that were on the shortlist this afternoon. I was fortunate enough to have a very useful meeting in Dublin just over a week ago as a result of co-operation with the Government in the Republic, where they made available a series of very senior officials in their Government to talk about the way in which their vacant land tax has been developed. It was both a very instructive meeting and a very encouraging one as well. They made it clear to me the purpose of their vacant land levy is not to raise money; it is to support the planning system and to make sure that, where hard work has gone into identifying pieces of land, making them fit for development, giving them the necessary permissions and so on, that those pieces of land do not then sit idle doing nothing. And they feel it's been a very successful piece of legislation in doing exactly that and, therefore, doing exactly the sort of things that Vikki Howells has outlined this afternoon.

A vacant land tax set and structured fairly could, I believe, help spur development in the Valleys, and housing, of course, is one of the five priority areas in our 'Prosperity for All' publication. This area too, though, Llywydd, has been slightly complicated by the budget on 22 November, because in it the Chancellor announced that he had asked Sir Oliver Letwin to chair an urgent review of the gap between planning permissions and housing starts in England. In what he said, the Chancellor said that he too was willing to consider 'direct interventions' if those were needed in order to make planning permissions that were extant turn into actual activity on the ground. So, here again, we are working to make sure that we have understood the work that will go on in England to see if it has any alignments to the ideas that we have discussed here in Wales. And a vacant land tax, I think, fits very well into that set of policy possibilities that are being opened up not just in Wales, but, clearly, across our border as well.