I welcome the Minister's engagement with Assembly Members but also wider civic society, who are interested in this issue, around tax devolution and, in particular, the really significant issues around the yield from the Welsh rates of income tax. I know she's speaking on Tuesday at the Wales Governance Centre, and also thank you for organising your own conference on 19 July, which I'm looking forward to attending.

The Finance Committee had Robert Chote from the Office for Budget Responsibility come in last week. You're paying, I think, £100,000 a year for work from the OBR in response to what was done by Bangor University. I was quite struck to learn at the Finance Committee the extent to which the primary responsibility for the tax forecast, and the numbers and the model that drove that, rest with Welsh Government but then OBR come in and challenge that and give a measure of quality control. But it's a huge responsibility.

We have this £1 billion so-called 'black hole' with Scottish income tax revenues and, although we haven't changed that—the Welsh rates of income tax is an area where the Government has stuck by its manifesto pledge to keep those the same—that doesn't mean that the tax yield can't change very significantly for matters potentially outside our control. You had Mark Drakeford negotiate the fiscal compact, which I think other parties and Members were complimentary about, but there are still huge uncertainties about how these revenues will develop. I just wonder what lessons the Minister is learning from what's going on in Scotland with this £1 billion so-called 'black hole' and, in particular, whether she thinks there's a case for needing a greater level of contingency and reserve in the spending estimates going forward, given those uncertainties and what we're seeing with Scotland.