it's a real cost, and a real benefit. I guess values vary on which is more important.
Overall the benefits for employees seems way broader than the benefits for the companies.
On a purely economic basis, wage transparency primarily benefits employers because it reduces how much they need to pay based on actual performance in practice.
Why would transparency reduce how much employers have to pay? Usually capitalists would make the opposite claim, by keeping salaries opaque, it's much easier for employers to underpay people, but you seemingly are making the opposite claim.
If I can see how much my employer pay others, doesn't that help me ensure I too get fairly compensated from the employer? How could the employer leverage this situation to pay me less than I already know I'm worth?
When wages are opaque, an employee only needs to justify their worth to the employer. Employers pay for value net of wages, so they are often happy to pay someone much more if the individual value generated justifies it. When wages are transparent, an employee needs to justify their worth to everyone else because a higher wage is tacitly reducing their wage. This creates social pressure separate from the economic argument.
Other employees are incentivized to maximize their own wages regardless if it maximizes value for the employer. And there are many more average employees than high performers. Employers can leverage this social pressure to cram down the wages of anyone who wants to be paid above average because they no longer have to defend a lower wage on a purely economic basis. Empirically, this is what happens.
Anecdotally, I've seen this play out countless times at companies.
Then your salary will be decided by lowest common denominator. Employer does not leverage this situation, employer reacts to the incentives this situation creating.
Why would it? That's not what happens in practice, and you have raw data to point at, with things like "Person A is half a fast as me, and earns X, that's why I deserve X+N", not sure why you think there would be another outcome here, and it's clear you've never experienced this sort of environment yourself.
You haven't sufficiently manage to enter the mindset of a Swede. Your salary information isn't "your data" in the first place, it's public information. The company is selling public information if you have this mindset, does it still make sense to make it illegal then?
I think what you want to argue for, is for salary information to not be public data anymore. Selling people's private data without authorization (or even handling it incorrectly) is already illegal and actively punished today when it happens, via the long and slow arm of the law.
That is not an opinion. That is a fact. It's not public information, and anyone arguing that is categorically, provably, wrong.
The entire country of Sweden can collectively come together and decide that 1+1=3, and I would give that about as much thought as these semantic games around private and personal data.
1. Everyone(1) shall be entitled to have free access to official documents.
2. Official documents are all(2) documents held and produced by the authorities.
(1)=Everyone includes everyone in the world, you do not have to live in Sweden or be a citizen and you do not have to identify yourself.
(2)=Some restrictions apply (natsec, medical, etc).
In short, most government databases are databases of "official documents", including the citizenship registry maintained by the tax authorities.
Downside: All the mundane information about you is public property; address, birthdate, tax records, school grades, drivers license, passport photograph, martial status, court cases and pretty much everything else you can't think of.
Upside: Applies to all politicians as well.
What is and isn't personal data is subjective, regardless what "truth" you believe you're sitting on. I won't claim you're right/wrong as there is no such concept for subjective things, I suggest if you want to understand instead of wave your hands around or whatever you're doing, you'd try to see things from another's perspective and forgo dogmas.
Ontological games are just that - games. Personal and public data is not an opinion, and it's not subjective.
I legitimately think that it's harder to have a coherent definition of a chair than to define personally-identifying vs anonymous data, and pretending otherwise is stupid.