So, he gives evidence to the House of Lords. Lovely. Who then say:
According to HMRC’s latest estimates, the total tax gap amounts to £36 billion or 6.5 per cent of total direct and indirect tax liabilities. Professor Richard Murphy challenged HMRC’s methodology, arguing that the figure is an underestimate. For the purposes of this report we use HMRC’s estimates of the overall gap.
That is, we don’t believe Spud. But there’s more!
Most of the evidence submitted to the inquiry challenged HMRC’s analysis of the behavioural effects of the measures arguing that the estimated tax gap reductions would either never materialise in full or might even go the other way.
Some argued that, to the extent that record-keeping would improve, the result would not necessarily be in the Exchequer’s favour.
That is, the errors in record keeping which drive Spud’s estimate are not all in the direction of less tax, it’s even possible that they, in aggregate, trend the other way, meaning that Spud’s estimates are even more wrong!
What then worries about our Professor’s intellect is that he quotes this to show that he is right……