The risk I'm concerned about isn't that my current employer will fire me. It's that if I switch to another job, I might not last long at the new employer.

That said, I'm doing the job switch thing anyway; not to get more money, but because I've grown to hate my career and am hoping to switch into a more creatively fulfilling one. If I can find such a job with a larger paycheck, of course I'll take it; but I'm also willing to take such a job with a pay cut if that's what's available to me in the new industry.