„Our empirical findings confirm our theoretical expectations. Using data from five waves of the World Values Survey, we uncover evidence that union members are more satisfied with their lives than those who are not members and that the substantive effect of union membership on life satisfaction is large and rivals other common predictors of quality of life. Moreover, union membership boosts life satisfaction across demographic groups regardless if someone is rich or poor, male or female, young or old, or has a high or low level of education“ (Flavin/Shufeldt 2014: 11).
The (significant) effect is remarkable: +.12 on a life satisfaction scale from 1 to 10 (highest satisfaction). The effect of being married is +.46. (Self-reported Health: +.58; unemployed: -.27; retired: +.29; church attendance: +.07 ; for these results of a OLS regression analysis cf. p. 18, table 1). The explanation of the authors, why there is a positive effect, goes like this: „… citizens lead more satisfying lives when they are afforded the resources and protections that membership in a labor union provides“ (p. 11).
Source: Flavin, P.; Shufeldt, G. 2014: Labor Union Membership and Life Satisfaction in the United States. Baylor University / University of Arkansas, October 2014; see also the article in German here: http://www.boeckler.de/53045_53052.htm