"However, it is well know that it is sometimes (often?) the case here in Qatar that different nationalities doing the same job are paid differently."

Agreed. That may be true, but:

1 - the survey does not provide any evidence to support this statement
2 - by extension, people are reading into it that a Brit does the same job as an Indian, the Brit is paid double.

For instance, when it comes to MANY jobs here in the GCC, people are paid within salary grades. Employees of a certain level will receive a salary within the salary band, but the difference will not be double.

All I want to say is that most people commenting on this thread have either not read the survey, or have totally failed to grasp the basis if the results. (And, unsurprisingly, they are the sames ones saying that they ought to be earning more....)

Regarding why different nationalities earn different amounts for the same job... well that's been done to death on QL. My only comment is that while they may have the same job title, they tend to have different outputs.