Right, so then location does affect the quality of the work provided. Although it then still is weird to base differentiated pay on cost of living / local marke

Right, so then location does affect the quality of the work provided. Although it then still is weird to base differentiated pay on cost of living / local market rates; surely those don't all correlate with the quality of the work delivered? If you can get an engineer with the same skills from Spain for less money than you'd pay for the equivalent in Germany, why would you hire the latter?