My opinion is that income solidarity should be achieved through the tax system. This way it can be fine-tuned to the wishes and needs of the society and everyth

My opinion is that income solidarity should be achieved through the tax system. This way it can be fine-tuned to the wishes and needs of the society and everything is "clean". Additional sources of "hidden" solidarity like my example with Alice are in my opinion unnecessary and counterproductive. Companies should be left to pay people exactly how much they value them to ensure maximum efficiency, then taxes can reduce these differences to the extent the society desires. Politics aside, even in a system where every company must have public salaries to avoid disadvantaging those who do, the system would still be inefficient. A company that hires only "Alice-level" developers can pay Alice 100 as they pay everyone roughly that amount. They don't suffer from this effect. A company that hires Bobs finds it hard to hire and keep some Alices (exactly what happened at my first job, I wasn't the first nor the last young guy in that position to quit quickly when I realized what the deal was) as long as it mostly hires Bobs. And Bobs also need to work somewhere. This basically gives companies a strong economic incentive to stick to a similar level of talent when hiring, which is a market inefficiency, and to developers of similar skill level to accumulate in the same companies. So with time, Alice ends up working at a company with other Alices and they are being paid 100, while Bob is working with Fob and Gob and being paid 50. This is actually an aspect of another, more general problem with salary solidarity: if you overpay your lower-value employees, and underpay your high-value employees, this gives the lower-value employees the incentive to take the job and stay forever, and the higher-value employees the incentive to not even accept the job or eventually leave for a job that doesn't underpay them. Over time, you're accumulating lower-value overpaid employees. Government jobs are an extreme example of this problem (in my country at least) as there is a high level of salary solidarity there. Paying people what they're worth in gross salary, and then achieving solidarity through taxes at least solves this problem within 1 country. It still doesn't solve it internationally (as the highly productive people still have the option to jump ship to countries with less solidarity, but this is not as bad as people are not as quick to emigrate as they are to switch jobs).