So your very substantive contribution to "they're abusing market power" is the observation "they could only do this if they have market power?"
And you're wanting someone else to go demonstrate to you that the single entity that is both 1) largest health insurer and 2) largest health provider in the country has significant market power?
I'll assume that this is legitimate ignorance and not a bad faith attempt to muddy conversation, and I'll direct you to a few resources where you can read several years of extensive investigative reporting on the myriad ways the pay-vider structure enables acquisition and exploitation of market power:
https://www.economicliberties.us/data-tools/unitedhealth-gro...
https://www.statnews.com/unitedhealth-group-investigation-he...
https://www.wsj.com/us-news/unitedhealth-medicare-fraud-inve...
https://www.wsj.com/health/healthcare/medicare-health-insura...
https://publicintegrity.org/topics/health/federal-programs/m...
You can also read the public filings of the payviders to read them bragging about their use of these techniques.
Here's direct reporting on the concentration itself: https://www.ama-assn.org/press-center/ama-press-releases/ama...
>I'll assume that this is legitimate ignorance and not a bad faith attempt to muddy conversation, and I'll direct you to a few resources where you can read several years of extensive investigative reporting on the myriad ways the pay-vider structure enables acquisition and exploitation of market power:
I read through the first 3 and can't tell how they're related, so I'm not going to check the rest.
>https://www.economicliberties.us/data-tools/unitedhealth-gro...
https://www.statnews.com/unitedhealth-group-investigation-he...
These only claims that united health is the "biggest", but that's not the same as having monopoly in a given market, which is needed for the scheme to work. Otherwise if you only have say, 30% market share, and your associated hospital charges sky high rates, you might be able to get slightly fatter margins on your insurance side, but you'll be losing money to other competitors that can out-compete you through greater economies of scale. I did a cursory search and their national market share in insurance is around 15%, which really seems tough to have the economics work out, especially given how capital intensive hospitals are.
>https://www.wsj.com/us-news/unitedhealth-medicare-fraud-inve...
What does "Medicare Fraud" have to do with the question that they're a monopoly or not?
This and the other links feels like trying to smuggle in a specific claim about what united health might be doing (ie. they're charging irrationally high prices just so they can pump their insurance margins), by pointing to a bunch of other shady stuff that they do.