> Unions often drive out workers at the benefit of those getting union jobs, lowering employment. For example, see [5] and similar papers.
This seems a bit misleading from the article you referenced:
“The researchers find that, for both men and women, more union involvement in wage setting significantly decreases the employment rate of young and older individuals relative to the prime-aged group (with no significant effects on the relative unemployment of these groups). In contrast, a larger role for unions has little impact on male-female employment rate differentials but raises female unemployment relative to male unemployment.”
Lower employment for the very young and very old is generally a good thing in places with a robust welfare state —- and certainly is overshadowed by the positives of unions, such as the lower rates of poverty, lower mortality and accident rates, and higher job satisfaction and overall wages as a percentage of productivity across many industries.