Odds of Hanging On
So, you've beaten out the competition. You're there at the NIH, a bona fide research scientist. What's better is that you have staying power. The job security is pretty good, since there will always be more questions than answers in the area of human health.
If you've set up a slew of experiments to figure out the genetic components to arthritis, chances are that you won't come up with one nice, concise answer in just a few months. More than likely, those experiments will bring up more questions, which will lead to more experiments, and you might need more scientists for that work.
But it's the NIH's budget that dictates how much equipment you can buy and how much risk you can take in the types of questions that you're asking. And the NIH budget depends on the national budget. If the U.S. is at war, or if there's some other economic disaster that needs more funding this time around, the NIH money can get slashed. When the money is tight, a boss might not be able hire a new scientist or keep all scientists on the payroll.