[endeavour]

Ok but the numbers you quoted assumed a linear relationship.

In no way is it "almost certain" that investment in the UK will decrease. The evidence currently suggests the complete opposite. Look at the performance of the FTSE100 since the referendum to see the flood of foreign investment coming into the UK listed companies thanks to the weaker currency.

I'd also point out that decreasing tax rates is the exact opposite of what the chancellor said he would do before the referendum.