Arguably a more efficient approach might just be to have a tax that adds on to corporate tax incrementally for every % of market share a company has above say 7-8%. Then dominant companies are incentivised to re-invest in improving their efficiencies rather than just buying/squeezing out competitors. A more evenly spread market would then, as a result, be against regulations that make smaller market participants less competitive, as they'd all be in relatively less table positions.
First, on the surface, this sounds like a terrible idea. Almost all ideas that I see on HN about economics fail with even the tiniest amount of common sense.
As a counterpoint: Look at very high value goods, like jet engines and MRI machines. I went for an MRI the other day and wondered to myself (then asked an LLM) what the international MRI market looks like. They are vanishingly small number of manufacturers and are usually dominated by a few international players. How are you going to apply this tax to non-domiciled (international) companies? Also, companies like General Electric, Mitsubishi Heavy, and Seimens are enormous and incredibly diverse. This idea falls apart quickly.
> Arguably a more efficient approach might just be to have a tax that adds on to corporate tax incrementally for every % of market share a company has above say 7-8%.
How is this more efficient? You'd still be applying all of the inefficient regulatory rules intended to mitigate a lack of competition to the smaller companies trying to sustain a competitive market, and those rules are much more deleterious for smaller entities than higher tax rates.
If you have $100M in fixed regulatory overhead for a larger company with $10B in profit, it's only equivalent to a 1% tax. The same $100M for a smaller company with $50M in profit is a 200% tax. There is no tax rate you can impose on the larger company to make up for it because the overhead destroys the smaller company regardless of what you do to the larger one.