The FTC has a page on it [1] but I wish there was more there given it's the biggest purchase of most of their taxpayers' lives. The reports section comprises three reports, two from 2007 and one from... 1983. Clicking "view more reports" links to a page with those same three. I know they've done more in this area but I thought that was worth a laugh at least.

[1] https://www.ftc.gov/news-events/topics/competition-enforceme...

Fun fact: NAR was the top lobbying spender in 2020 with $84B. Second place was Chamber of Commerce at $82B. Third place was $26B, or less than one third of NAR's spend.

https://infogram.com/1pyy66emdxryq1c3yez9wqvxp2by3p7pgn3

I only saw those stats recently but felt realtors are likely a very vocal and substantial constituency for every representative.