Comment by chii
> anybody can sue them.
who bears the costs of this suit?
And who determines what makes for a good market share size to be the threshold?
And by having such a rule, an industry that would have higher efficiency to when consolidated would not be able to (but you wouldn't know). It's a bad set of policy imho.
A better way would be for gov't to increase competition by adding supply, or demand, whichever one is the bottleneck to competition. If a company, such as AWS, is getting a lot of marketshare, but their profit margins is still high, then the gov't should incentivize competition by funding or giving loans to businesses that want to compete with AWS.
However, if AWS's profit margins, even at high market share, remains very low (e.g., amazon's commerce side), then there's no need for the gov't to "step in" at all, as there would be no incentive for any competitor to try enter the market due to low margins.
> who bears the costs of this suit?
The goal is to not have it happen, because the company is going to see that they're only slightly below the threshold and voluntarily split themselves into smaller pieces and buy themselves a safety margin because if they don't everybody knows the lawsuits are going to vaporize them once they exceed the threshold.
> And who determines what makes for a good market share size to be the threshold?
Anything in the vicinity of 5%-15% would be fine.
> And by having such a rule, an industry that would have higher efficiency to when consolidated would not be able to (but you wouldn't know).
This is extremely rare and the circumstances where it happens aren't a mystery. It's when entering the market has extremely high fixed costs but then the unit cost of usage is negligible, e.g. it costs a huge amount of money to install water and sewer but then the incremental cost of someone washing their hands is insignificant.
For those things you either have the government do them, or if it's a private company then it's a regulated utility which is completely banned from anything that even vaguely resembles vertical integration as the price of being allowed to have more than the threshold amount of market share.
> A better way would be for gov't to increase competition by adding supply, or demand, whichever one is the bottleneck to competition.
The problem is generally caused by the incumbents capturing the government and then enacting rules that inhibit rather than increase competition. That's why you need anyone to be able to initiate the lawsuit, so they can't capture the government department which is supposed to be thwarting them because then it's the entire public.