I think more of an institutional problem than a human one, that things will be resolved faster than they do, especially in the public sector.

Yeah, that's a great question.

In a sense, things haven't changed.

I mean, economic variables, if you like, play out over long-term horizons, as you say, medium and long-run horizons, when in reality, any government can only impinge on that in a short time.

unless they are re-elected and re-elected.

So to some extent that's not changed and it's not different now than it was 50, 80 years ago.

I think, as you say, what's happening now is certainly some of the choices that our modern advanced economies face tend to emphasise some of the, if you like, and this has been commented on quite a lot, tend to emphasise the zero-sum nature of some of the decision-making that happens in policy.

Now, if you could provide a piece of advice to people who are maybe starting in a new leadership role at one of these important public institutions, what would that be? It's always difficult to kind of

But could you perhaps spell out to us the scale of the challenge that the government has to face? And of course, in this instance, it's a Scottish government problem, but it is consistent with problems that the UK faces overall as well.

So yes the fiscal challenge is one that affects actually quite a lot of advanced economies and the UK isn't alone and the Scottish issues kind of derive from the UK issues in many respects.

So if you look at the International Monetary Fund it will tell you that you know the level of debt and indebtedness of major economies is one of the biggest issues that many of them face and that's to do with the fact that many advanced economies with the exception of the US perhaps have grown much more slowly over the last 20 years and if you grow your economy more slowly then it means that you find it more difficult to fund spending.

So if you look at the Scottish position in particular, obviously we had the last spending review in the UK and that defines part of the resources of the Scottish Parliament.

The Scottish Parliament then has to decide on how it's going to use income tax and some minor taxes to then offset that, meet those spending commitments.

And as you say, essentially, 4.8 billion is the gap that exists between the Scottish, the outgoing Scottish government's medium term financial strategy, which they set out just before the election, and the likely available resources.

Now, you're absolutely right.

Surely we have got to this position because in the entire devolved era, politicians have simply been concerned with the spending of money essentially for populist and electoral reasons and at no point actually saying what does this do in terms of creating the kind of society that we want to create and the only thing that we've now got with this five billion pounds black hole in a sense is the inevitable consequence of politicians who never face reality.