https://www.johndcook.com/blog/2009/12/23/why-programmers-are-not-paid-in-proportion-to-their-productivity/

The most productive programmers are orders of magnitude more productive than average programmers. But salaries usually fall within a fairly small range in any company. Even across the entire profession, salaries don’t vary that much. If some programmers are 10x more productive than others, why aren’t they paid 10x as much?

Joel Spolsky gave a couple answers to this question in his most recent podcast. First, programmer productivity varies tremendously across the profession, but it may not vary so much within a given company. Someone who is 10x more productive than his colleagues is likely to leave, either to work with other very talented programmers or to start his own business. Second, extreme productivity may not be obvious. This post elaborates on this second reason.