well, let's see here.
If I hire , for example, a driver from the UK, this driver will have certain qualifications.

1. He will know where he is going, or, if not, he will find out, by himself, BEFORE actually getting into the car.

2. He will take care of the car. If there is something he does not know how to do, he will find out. By himself.

3.He will open the door for his employer, and close it.

4. He will make sure that the environment, in this case the car, is pleasant to be in for his employer.

5. He will always be on time and available for his employer, as agreed in the contract.

Just a few points .

Now, if I hire a driver in Qatar,he,

1. will not know where he is going, despite telling his employer the opposite and furthermore expecting his employer to guide him.

2.He will not be able to take care of the car, leaving this to his employer .

3.Being curteous , as in opening or closing car dorrs, is not understood, even if reminded of frequently.

4. The car environment is none of his concern, in some cases discomfort to the employer is caused by the driver.
5.Being on time has to be constantly re or enforced.

Just a few differences why a driver from the UK , where certain qualifications are a must,would be paid much more than a driver from another place where these qualifications may not be seen as important.

And this is just one example, that of a driver.
There are many more professions where this exact same thing is applicable.