In response to the Treasury’s report on the costs of Brexit (and, obviously, to my blog post covering that report) a group calling themselves “Economists for Brexit” published a pamphlet which they claim contains a more reasonable estimate of the impact of Brexit on the UK economy.
Unsurprisingly, they find that, contrary to the Treasury’s report (and, indeed, the vast majority of economic reports published on this issue), that Brexit would benefit the UK economy by increasing GDP growth by about 0.5% points per year on average (with the majority of this increase coming in 2020, the final year of their forecast).
Equally unsurprisingly, their estimate is fundamentally flawed. In an impressive attempt to hide these flaws, the report contains only a two page summary of the model they have used to obtain their results, but even then the numerous flaws are apparent.
First, the report assumes that leaving the EU would mean that the UK would be able to remove EU-set trade barriers to non-EU countries, but would still keep the same terms-of-trade it currently has with EU countries. Moreover, it assumes that all trade barriers will reduce by half over the next five years. These assumptions drive the report’s “finding” that Brexit would increase UK living standards by 3.2% by 2020. However, the report does not provide any evidence to support the validity of either of these assumptions. Indeed, there is plenty of evidence to suggest that they are not valid – for example, they assume a rate of decrease in trade barriers not seen since the 1960s.
Second, the report assumes that the 0.8% GDP net saving from the UK not having to contribute to the EU budget would be passed-on entirely to taxpayers in the form of an income tax cut. This is extremely unlikely to happen – due to the current government’s austerity policies, any savings from Brexit are likely to be used to reduce the government deficit rather than hand out a (potentially politically damaging) tax cut.
Third, not only does the report assume that there would be a reduction in regulation if the UK were to leave the UK (which is an unproven assumption), the report then assumes that this reduction in regulation would have exactly the same effect as a 2% point decrease in the employer rate of NI. One hopes that those writing the point must have released how barmy such an assumption is – the report doesn’t contain even a passing attempt to justify how a decrease in regulation would have exactly the same impact as reduction in employer NI. Indeed, it is barely possible to conceive how anyone could think this was a reasonable assumption.
Anyway, moving on. Finally, the report assumes that the government deficit is unchanged due to the aforementioned assumptions resulting in the government’s revenues not changed. However, this fails to recognise the possibility that some of the money that was spent on EU goods and services previously could now be spent on UK goods and services, thereby potentially increasing tax receipts. Conversely, the report also assumes that non-UK people and businesses won’t decide to move away from the UK, which would result in a decrease in tax revenues.
And all of this is to say nothing of the fact that the report has excluded countless other factors that could be detrimental to the UK. For example, the report does not even mention the potential impact Brexit could have on immigration (note that the vast majority of studies find that immigration is beneficial for the country to which immigrants relocate and this is even true for low-skilled workers in that country). Nor does it cover the costs associated with the uncertainty that would be created and persist for a number of years regarding exactly what form of agreement between the UK and the EU would be put in place post-Brexit.
In essence, the study published by the “Economists for Brexit” group is so full of holes it is no surprise that they were only able to find eight professional economists to support it. Contrast this to the almost 200 economists (including yours truly) that are signatories to a letter in the Times stating that “[l]eaving would entail significant long-term costs.” That in itself should be damning enough.