How did deflation play a role in the rise of unions?

I think it's In the early 1930s, as the nation slid toward the depths of depression, the future of organized labor seemed bleak. In 1933, the number of labor union members was around 3 million, compared to 5 million a decade before. Most union members in 1933 belonged to skilled craft unions, most of which were affiliated with the American Federation of Labor (AFL).