Earlier quoted context omitted.
What power would a union have if the company is willing to close the unionized location? If they were required to keep the store "open" but the union strikes, the union is basically closing the location for the company.
It's a power imbalance. Starbucks can close one trying-to-unionize location because they have 3 others in a few block radius in some cities, and in doing so ensure the other 3 stores are too scared to unionize. If all 4 stores in a town unionized, Starbucks can withdraw from the town because they have 16 stores in a neighboring city, so and in doing so intimidate them. There is no equivalent behavior a worker can hav…
Network effects for me, but none for thee.