Curious about how the business responds to workers leaving/joining. I expect that a worker wanting to leave needs to find someone to buy in, and the new worker has to be approved by the collective. This sounds like a recipe for inflexible departure.
Next, expansion. I expect expansion is a tricky proposition because it means dilution, which is both a hard sell and a risk to the workers.
The worker leaving doesn't have to find someone else to buy in. They just leave and receive the value of their investment. The cooperative finds someone else to buy in. Usually there are lots of people looking to do so.
People save up for years so they can apply to buy in and work at Mondragon.
Next, expansion. I expect expansion is a tricky proposition because it means dilution, which is both a hard sell and a risk to the workers.