The real problem is looking at compensation in isolation and not as a function of productivity. If someone aged 42 is only as productive as someone aged 22, it

The real problem is looking at compensation in isolation and not as a function of productivity. If someone aged 42 is only as productive as someone aged 22, it's perfectly reasonable to offer them only the same salary for the same job. Of course, unless the person aged 42 has wasted 20 years of their careers (which, I concede, some have) it is highly unlikely that their productivity is really still the same. A 42-year-old developer who has 5x the productivity of a 22-year-old developer and much more general business experience as well but only wants 3x the salary is a steal, unless you're only looking at the $$$.