Economists are a smart bunch but still find it impossible to manage all of the variables that determine how the economy works.
This analysis from Global Demographics is about the impact on the reduction of immigration into the UK and how it impacts economic growth.
To give you a feel of how important immigrant labour is to the UK - between the period January to March 2015 and January to March 2016 the number of UK nationals working in the UK increased by 185,000 compared to the number of non-UK nationals increasing by 229,000.
So if if the number of immigrants is reduced then it will undoubtedly impact the way things work.
What was missing from the Global Demographics forecasts was any account of what is happening as people stay in the workforce for longer periods.
The data from the UK Government showed that the number of working pensioners has risen from 396,000 in 1984 to 1.14 million last year. It also looks as if early retirement is in decline, with the number of people aged 50 to 64 in work rising by 57% to 8 million.
Now I don't think for one minute that the number of immigrants working in the UK will be reduced by anything like what is being suggested. If that happened then the hospitality and care industries would collapse. It would also make a hell of difference to the logistics industry where so many drivers come from outside the UK,
Because so many older people are ill prepared financially for retirement I think you are going to see a lot more of them in the workforce working alongside their overseas cousins.
Now the big question is how well adapted are the workplaces for all these older workers. Answer to that one is simple. They aren't. Dick Stroud