How commonly do researchers spend a long time (>10) years on soft money? In Academia, a soft money research position is one where uncertain money comes from an external source.  The employee or xyr supervisor/boss might need to secure funding every couple of years or so, in order for the position to continue.  The way out would be tenure or a government job.

An obvious soft money position is the post-doctoral fellowship, but many post-docs might not find a faculty position directly.  For example, if the University of California at Los Angeles (UCLA) advertises a soft money assistant researcher position, they have a defined path of promotion steps.  UCLA defines four steps of assistant researcher (2 years max), three steps of associate researcher (2 years max), and nine steps of researcher (3 years max until step IV, possibly indefinite from step V).   If coming in at step I of assistant researcher, it might, theoretically, take 4*2+3*2+4*3=26 years of positions in steps of 2 years (first 14 years) and 3 years (last 12 years), until one might be appointed indefinately, if I'm reading things correctly.  Needless to say, not ideal from an employee's point of view.

Although time-limited positions and soft money might not mean exactly the same thing, I suppose they often go hand in hand.  That raises the question: how common is it for researchers to spend a long time, say more than 10 years, in soft money positions?  It's one thing to "drop out" of Academia when finishing a PhD at 28 years, it's another thing to move from postdoc to assistant researcher to associate researcher, only to finally discover, at age 45, that you're not good enough for tenure, and lack the necessary skills and experience for a teaching position.  Oops.

In Science, Technology and Engineering (STEM) fields in the USA and Canada, how common is it for researchers to spend more than 10 years in time-limited soft-money research positions?
In the U.S., at least, long-term careers on various forms of "soft money" are a lot more common than it looks from inside the "core" academia of graduate school and tenure-track faculty positions.  In reality, the research ecosystem is very complex, with all sorts of niches that aren't necessarily apparent from the outside.  My own experience as a grad student was that I didn't even know any of these options existed until a colleague reached out and invited me into the non-traditional side of academia.

I know of many people who have had long and fulfilling careers, all the way to retirement (if they ever really retire), entirely on soft money.  Some of them have been with a single university or company for that entire time.  More often, they shift around from position to position over time, between university, government, small company, large company, consultancy, foundation, non-profit, standards organization, etc., in patterns dictated by the evolution of those organizations and how the research opportunities are shifting.  Unlike with postdocs, this often doesn't require moving, particularly near a high-tech hub: Boston and the Bay Area are obvious examples, but many large cities have research sectors that interact with the local universities in all sorts of non-obvious ways.

The distinction between "soft" and "hard" money is not always as obvious as it appears, either.  For example, there are organizations that pool soft-money risk, or have core positions that are effectively hard because they are pooled between many external grants.  Even university professors can often have the option to "soften" their positions by buying out of teaching responsibilities.

From my experience, it seems that there are three main classes of soft-money researcher, showing up in all of these environments:


Primary investigators: just like normal faculty PIs, but with a higher cost and no teaching commitments.  A PI who can establish a strong research direction and funding stream can hold a position nearly as secure as tenured faculty.
High-skill implementer: these are people who don't necessarily lead their own projects, but who work full-time for PIs in executing projects.  Engineers, analysts, programmers, lab technicians, etc.  Really good implementers are always in high demand for research, and can have a long and productive research career when teamed with the right sort of PIs.
Exploited labor: these are either implementers who haven't developed/proved their skill, people trying to become PIs who haven't made it yet, or researchers who are stuck in an exploitative environment.  This is the type of soft money that seems to be most common in certain parts of traditional academia and can be "eternal postdoc limbo" (or its fake-hard-money cousin: "adjunct faculty limbo").  Unfortunately, it can often be hard for a researcher to tell if they're in this category and whether it's a passing stage or a trap they need to break out of.


Life in these worlds can be very different than in the teaching-centric parts of academia, but an awful lot of interesting things happen in them, and it offers much more variety in career options for a graduating Ph.D. with an inclination to research than I think most people know about.