A report has just come out on the economic impact of faith communities in Wales. You can read a summary headline page of Counting for Communities here, or see the homepage for the report here. The report estimates that faith communities in Wales contribute £102m to the economy each year, a figure which would equate to over £2bn if projected up to the whole UK.
There's an article at Christianity Today, and a similar survey on the North West from a 5 years ago also online. This estimated the contribution of faith communities in the region at just over £90m. Welsh churchgoing is significantly higher than in the UK, which might explain why, with half the population of the NW, faith groups make roughly the same economic contribution.