Anecdotally, the things that have made me most likely to stay at a job is seeing a few high-profile people leave, only to come back with horror stories about their other jobs.

I honestly believe I work for an amazing company so the metaphor may not be perfect, but if you want to increase confidence temporarily you could certainly try to manufacture these circumstances. In my case I think they're genuine, which does actually give me significant pause any time I think about how much of a raise I might get, or where else I might go.