Hope Labor: The Role of Employment Prospects in Online Social Production looks at the motivations behind "hope labor", which the authors define as:
"... un- or under-compensated work carried out in the present, often for experience or exposure, in the hope that future employment opportunities may follow ..."
The paper itself is very academic and most won't want to wade through it.
But the concept of hope labor is clearly increasingly common. The rise of unpaid internships and what we call The Tryout Economy are examples.
The reasons for the increase in hope labor are straight forward.
From the hiring firms perspective, hope labor lets them tryout potential employees prior to hiring them to make sure they are getting capable workers with the skills to do a good job.
From the workers perspective, hope labor provides a path to build skills and prove competency. It may also be the best or even only path to employment.
Hope labor is yet another example of risk being shifted from institutions to individuals. In this case risk is being shifted from hiring companies to job seekers.
The risk shift is one of the the most important and impactful societal trends we follow. It's also one of the least covered and discussed.