That’s the title of a paper by Michael Kremer and Benjamin Olken. The bottom line is:
…a union that implements workers’ preferences will not be evolutionarily stable.
The union that survives must either extract fewer rents for the workers (thus lowering anti-union expenditures from the employer, or helping keep the employer in business) or spend excess funds on organizing and bolstering union membership in the broader economy. A union that spends on membership and organizing drives tends to spread from one firm to the next. If a union were truly controlled by its members it would take lots of current rents with little concern for the longer-term future of the firm or for the longer-term future of the union.
Here’s a neat paragraph:
The dynamics of unionization levels also bear a similarity to those under the Susceptible-Infected (SI) model of epidemiological dynamics…In that model, new potential hosts are born uninfected; the chance that they become infected increases with the number of hosts already infected; and once hosts are infected, they stay infected until they die. Note that this comparison is purely positive, not normative.