Budget Responsibility and National Audit Bill [HL]

My Lords, it should be convenient, as has been suggested, that we discuss Amendments 26 and 39 at the same time. This is an important aspect. We are going into a situation where the Government have an official forecast, but a great many other forecasts will be produced at the same time. The helpful document produced by the Treasury, Forecasts for the UK Economy, shows just how many other independent forecasts there are, but the OBR one will clearly have a particular and unique importance. If it is going to be compared with forecasts by other forecasters, we need to know the assumptions on which the official forecast is based, because we all know that the assumptions that are made essentially determine the outcome of the forecast. I realise that the charter also refers to the assumptions being spelt out but it seemed more convenient in this instance to put that into the Bill. Indeed, I am inclined to think that this is so important that it ought to be in the Bill rather than in the charter. Since there seems to be general agreement in the draft charter that this should be so, however, I am not clear where these assumptions appear in the first example that we have been given of an OBR report, Economic and Fiscal Outlook—November 2010. It would be helpful if we were told exactly where the Government believe that these assumptions are being spelt out. The other amendments also relate to what one might in simple terms describe as the ““model””. In this context, I am not clear precisely what model is being used. The Treasury had a model, of course, which was published and was used by various outside organisations, including the so-called ITEM group. Are we to understand that the OBR forecast will totally replace the Treasury forecast that used to appear in the Red Book? If so, is the OBR none the less going to use the same model that the Treasury used, or does it have a model of its own? In either case, it would be helpful if my noble friend could place in the Library, or publicise more widely, exactly which individual model is being used; we would then have a better basis for comparing it. Are we also to understand that if the Treasury model disappears, the ITEM group—for the benefit of Hansard, I should point that it is spelt out in capital letters rather than just being referred to as the ““item group””—will go on using the Treasury model, or will there be a replacement? I agree with the opening remarks of the noble Lord, Lord Eatwell, about the importance of getting the technical aspect of these matters straight. The technical arguments are important if the OBR’s forecasts are to have the credibility that they ought to. I would be grateful if my noble friend could respond to those simple points so that we understand where we are going in the future. Perhaps he might point out to me where the assumptions are specified in the November document that was the first example of the OBR’s work.