I accidentally upvoted instead of downvoted. It it of course nonsense that you are adding to the salary. If the employer is willing to pay £600, then you are taking X% of £600 and giving the employee (100-X)% of £600. The £500 figure that you are "adding" to is just an imaginary number that has no real significance.
Do recruiters really take as much as 20%? This seems ridiculously high to me. How much of their time are they investing compared to the employee?
An employer is willing to pay an extra 20% to save themselves the time and effort of having to source & interview the hundreds of applications themselves.
As for recruiters taking 20%, that's a comparitively low figure for such a high daily rate. If one of my clients was requesting a £500 a day calibre candidate I wouldn't touch it for anything less than 30% in reality.
We are providing a service, plain and simple. The service fee is calculated in relation to the calibre of candidate as the more senior the candidate, the more difficult they are to find.
I'm sorry, but this is an accounting fiction. The cost of an employee to an employer is the total cost; dividing up the total cost and ascribing it to this or that is irrelevant from the perspective of the employer, and disingenuous from the perspective of the employee.
In the US we have social insurance taxes which are sold as having an "employee" portion and an "employer" portion, but this too is just accounting fiction:
Perhaps I'm misunderstanding what you mean by 20%. If you get an employee for a year, do you get 20% of the yearly salary? So you have to find 5 people per year to get paid as much as the people you find? (on average)
If so, does that truly not sound ridiculous to you? If all people got employed through recruiters then the recruitment business would make up about one fifth of the total economy!
Do recruiters really take as much as 20%? This seems ridiculously high to me. How much of their time are they investing compared to the employee?