> it should be to break them into smaller pieces so they actually have to compete with each other.

I wonder what the world would look like if you just prohibited any single organisation or controlling group over a certain size. Say you couldn't have a company over 100 million in value.

You could still have massive projects like semiconductor fabs and steelworks but they would have to be collectives of dozens of (competing) smaller companies. Efficiency may take a hit especially in the verticals but would it be be outweighed by greater market dynamism as no one company can dominate a sector and crush out competition and innovation?

Maybe provide a tapered relief for worker salaries and/or capital outlay to encourage employing people and building things rather that hoarding cash in financial structures.

Obviously this is impossible to do as the global system stands, but I find it an interesting thought experiment.

> I wonder what the world would look like if you just prohibited any single organisation or controlling group over a certain size. Say you couldn't have a company over 100 million in value.

What you want is a maximum market share percentage, and for it to be something like 20%, with the market definition never including products that aren't actual substitutes for each other, e.g. the market is never "brake pads", it's "brake pads for Honda Civic", but that could still have a dozen independent suppliers or more.

> Efficiency may take a hit especially in the verticals

It's not obvious that this is even a thing at that scale. Economies of scale (amortizing fixed costs over more units) have diminishing returns once the fixed cost contribution per unit is already small, whereas diseconomies of scale (bureaucratic overhead, entity size exceeding Dunbar number, office politics, etc.) gets worse with size, and the latter comes to dominate long before anything reaches the scale of a global monopoly.

> Maybe provide a tapered relief for worker salaries and/or capital outlay to encourage employing people and building things rather that hoarding cash in financial structures.

Let worker salaries always be deducted in the year they're paid out instead of the existing nonsense where R&D money which is already spent can't immediately be deducted.

> Obviously this is impossible to do as the global system stands, but I find it an interesting thought experiment.

Why is it impossible to do? The US or EU alone or any large enough coalition of other countries together could make the rule apply to anyone who wants to sell into that market, because they have an economy large enough that either the incumbents would comply or having excluded them for not complying, the market size would be enough to sustain new domestic suppliers.