It used to be true that most people preferred working at large organizations and big brands as these were associated with additional benefits and fairer pay. However, that advantage that larger companies had, started eroding the 1980s but has fully taken effect now. Firms with more than five hundred employees were usually better at talent management, paid higher salaries and smoothened the deal on the factory floor with additional benefits to save themselves from any perceived ill-effects of unionization. However the trend of outsourcing support duties and downsizing has meant that a lot of positions where workers enjoyed this leadership simply got transferred to contractors. Technology changes and globalization further exacerbated this issue. Thus the ill-effects have been faced more on the middle and lower skill brackets.

Source:http://knowledge.wharton.upenn.edu/article/no-longer-pays-work-larger-firm/