Gregory's Server
@alan Looks like we only have ~50% mapped in the UK 🇬🇧. Rule of thumb from Nottingham figures suggest 1 hairdresser per thousand people, which gives an estimate of roughly 60k (assuming under 5s don't use them), which is close to figures here https://www.nhbf.co.uk/documents/industry-statistics-2023-sheet/1a5-industry-statistics-sheet-2023.pdf
@alan the other approach is bavk-of-the-envelope. If we assume 60 million customers getting hair done 4 times a year and taking 20 minutes, we get 80 million person hours or roughly 50,000 FTEs. Obviously very conservative values, but given most salons are sole traders it gives a reasonable approximation.
I'm now going to have to get my hair cut so I can interrogate my hairdresser about her customer mix.