But without a monopsony how do these choose your own adventure unions have any real bargaining power?

In countries where meta-strikes are legal, the unions cooperate on basic rights, and strike together when needed. Such coordination is explicitly illegal in the US, and has been since the '30s (IIRC).

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reverius42 a day ago | parent | prev [-]

It sounds like they'd at least have more power than a single-employer union, by virtue of being larger and having more resources.

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jgalt212 a day ago | parent [-]

I'd much rather run a factory where only 10% of my workers may strike than one where 90% may strike.

	▲	s1artibartfast a day ago \| parent [-]
		It is usually like 2 or 3 and they will strike together. Having multiple keeps the unions in check and arguing for a pay raise for 60% of workers and nothing for 40%. I that case, the 40 would form their own union