Everyone seems to be struggling with the government’s stated position on these documents, claiming that there have been obvious inconsistencies. I will argue that on this sole point, there have been no inconsistencies and in fact, the position of HMG is economically correct.
By “everyone,” I mean the Financial Times and noted QCs as well as the entire Twitter commentariat. So that really is everyone.
The general position seems to be something approximating to the following. “Davis said HMG had done a lot of work (“57 documents”) on the economic impact of Brexit but then when he was asked to provide it, changed his position to the diametrically opposed one of “there are no documents.” ” If he had said that, he would clearly be inconsistent and incompetent. But, he did not say that.
The key to this is understanding the formal definition of an Impact Assessment. According to Davis (and which I accept):
An Impact Assessment must include a “quantitative forecast of economic outcome”
This means that for an Impact Assessment to have been produced, a team of economists and sector experts has produced a complicated spreadsheet modelling cashflows. Efforts have been made to see what the effect of tariffs on a particular sector would be. Finally, and critically, assumptions have been made as to exactly what percentage of trade will be lost, to what extent this will be offset by other factors, and what the levels of various key parameters will be, such as GDP growth in the UK and the EU, CPI in various locations, and the level of employment and the flexibility of workers. If a document does not have such a “quantitative forecast of economic outcome,” it is not an Impact Assessment.
Davis admits that no Impact Assessments have been made. There has been, though, a great deal of assessment of the economic impact of Brexit. These are the 57 documents. Note also that these documents can have detailed numerical underpinning but still not meet the formal definition of being an Impact Assessment. Just because something considers the impact of Brexit economically does not make it an Impact Assessment. We see this when Davis says that the fact that a document contains the word impact is not sufficient to make it an Impact Assessment.
Should HMG do Impact Assessments? No. They are, again as Davis says, of limited value. This is because we have little idea of what CPI or GDP are next year, and we have absolutely no idea over the 30 year horizon of relevance here. I discuss such difficulties of forecasting in a precise way in my new book (see for example pp. 79-80):
So, it is now clear that there is no inconsistency in the position taken by SecState DEXEU and it is in fact economically appropriate.