My guess is that the main application area this should be investigated for is promotion / facilitation in developing countries. [I don’t see an obviously good way to shift US/European policy to promote this, and would rather limited reform effort be spent towards something like land use / permitting / voting reform. EA organizations are generally either non-profits (where making them ’co-op’s seems unlikely to have large effects) or for-profits where limiting the upside to owners is probably desirable (since the for-profit’s EA value is typically earning to give / it being easy to hire non-EA workers for a company with EA owners).]
Some scattered thoughts as trailheads:
Most of the evidence base is probably in developed countries, and so it makes sense to run more experiments / figure out which conditions favor co-ops. [The traditional ‘family firm’ / ‘corporate family’ is, in many ways, a co-op, just with a much higher barrier to entry.]
Legal agreements are harder to execute and trust, especially at lower levels of wealth. [See The Mystery of Capital for more.] Having boilerplate co-op formation agreements (or administrative support for forming co-ops) for various countries will probably touch one of the main pain points for creating them.
Management consulting firms tend to be more effective in developing countries than developed ones (as they’re more likely to be able to point out a ‘basic’ principle or practice that the managers would have picked up in business school in the developed world, but is not common practice in the developing country). It might be possible to find (or found) such a firm focused on doing consulting in developing countries, and have them push formation as a co-op. [My guess is it’s easier to get entrepreneurs to form new businesses in a new format than reform existing businesses as them, but this is an empirical question that’s worth checking.] This might also be a good laboratory for random assignment (noting that you can only randomize whether you advise they become a co-op, not whether they actually do, and places where it’s a worse idea might be more resistant).
Relatedly, one of the big transitions is from ‘owner as whip-cracker’ to ‘owner as optimizer’ (see here for more); it may be that co-ops have an easier time with this than traditional firms, and this gives them a more substantial edge in places where that transition is incomplete. [Given that this is both a cultural and a financial change, my guess is this edge is actually not that large; Taylor is pretty clear on incentives needing to be individual to have the largest effect.]
It might be possible to set up a microlending program that focuses on creating co-ops, or partially buying out existing owners to donate stake to the workers. [I imagine a core challenge here is that workers are not going to be excited about the risk associated with being in a co-op, and it takes some external energy source to get over the activation barrier here.]
re: whether socialist firms work, I think the main problem is going to be managers making worse decisions because they’re more blended with the interests of labor. For example, a firm where decisions are made by the workers-as-a-whole probably wants to pay workers according to their average product instead of their marginal product, but this means they’ll hire too few workers (as average product is larger than marginal product, and so the ‘last workers’ are more expensive in the average-product firm).