In the meantime, yet another economic analysis, this time from the Office for Budget Responsibility, suggests that even in an optimistic scenario, No Deal sees a short-term hit to the UK that amounts to about 2% loss of GDP by the end of next year.
I can understand that people might choose to dispute this analysis, mostly because it's inconvenient to their case, but there's no sense in pretending that there isn't a serious, and well-supported, rational argument that a No Deal exit is bad for the UK. It's not about pessimism, it's about evidence.