I did promise you the last word, but given as you asked a fair question at the end, I'll answer that:
Q/ What would it take for you to admit that Brexit has been to the detriment of the UK?
A/ Economically, I will be looking to see how the UK compares vs advanced western nations in the EU (Sweden, Italy, Spain, Germany, Portugal, France, Belgium etc..broadly the eurozone) in the coming years in terms of things like GDP growth, unemployment, debt, wage growth, inflation. ie, the key economic indicators which provide the best wider picture.
Socially, it's much harder to analyse, but I would like to see reduced inequality, greater confidence, a happier society (almost impossible to assess) a more content, less anxious society, greater health outcomes etc.
So that's how I will assess it in quantitative and qualitative terms.
We don't agree, but I am sure we both want more or less the same things for Wales and the UK so lets home it works out.
