Most surveys are bollocks as they rely on people telling the truth.
Surveys about what people earn - unless it can be independetly verfied - are total bollocks.
Surveys about paid sex are total bollocks.
Put the two together and you have total total bollocks.
Complete waste of time, money and effort. They will never accurately know how many prossies there are or how many men pay for sex. What about someone who has only prossied a coupleof times a year? Does she count? I haven't paid for sex since August? Do I count? If I was asked today if I pay for sex I would have to say no. The same if I was asked three months ago. If I was asked three months hence the answer may be different. Although I doubt it!
Apart from blokes I have met through punting hardly any other males I know have told me they have paid for sex. A couple of mates in the dim and distant past. I still know these pair and neither as far as I am aware has punted for over 25 years. Both reckon it's a waste of money rather than abstaining for moral reasons. Do they count?
These 'surveys' can never be more than probably wildly inaccurate estimates. However, if anything, like with most things - population, illegal immigrants, crime figures - the number of prossies and punters will most likely be higher than those published. With regard to earnings this will be even harder to estimate. Yes a good popular, organised prossy can easily earn £50,000+ a year. However many are not as busy as we often think and are thoroughly disorgnaised.
I have hardly ever failed to get an appointment because someone was too busy. Whilst a parlour girl might be lucky to clear £200 a day, particularly if there are numerous girls there and few punters. She will need 4- 5 clients per day, which doesn't sound many, but if she is competing with 3/4 other girls isn't always achieveable. The majority also don't work every day so they are probably on average ish earnings £20 - £30k. It is of course also highly unreliable. Many times I have been in parlours with 3, 34 or even 5 girls sitting around waiting.
As I say probably very few work every day. They don't want to get a sore fanny!