A well-known problem with GDP is that it does a poor job of counting income that people don’t want counted. In particular, the income of people who choose jobs that are illegal.
So, following the lead of the EU, the non-member UK is going to start including estimates of the value added of the illegal drug trade (£3B) and prostitution (£7B).
Those figures amount to 0.2% and 0.4% of GDP. If you ask me … that’s too small.
The source article is gated, but you can get what you need from this post at Huffington Post.