You are assuming there's different work delivered. The null hypothesis has to be that there is the same work delivered, unless there's evidence to the contrary.

You are assuming there's different work delivered. The null hypothesis has to be that there is the same work delivered, unless there's evidence to the contrary. And it's clear getting unbiased such evidence is difficult, at best. Hence, a reasonable baseline is same pay. Note that they have different levels of positions, so "the same" is only valid within a level. If you are so awesomely skilled and productive, presumably you will have a higher-level position. You are focusing on one aspect to the detriment of others. If you have individual (i.e., arbitrary) salaries that lead to people who are better negotiators getting higher salaries for reasons that have "nothing* to so with work delivered, how can you say that is fair. The world is a big optimization problem, and in my opinion the policy described in this post does a pretty good job at that optimization.