I've left academia and returned, then left and am returning again. Thanks to the sequester, the NIH and NSF funding situation is bleak--I know successful PIs who currently have zilch. They're pursuing consulting contracts to make ends meet--at least in engineering this is possible. At this point it is trolling--pure sadism--to suggest that confidence and hard work will overcome the destructively competitive working conditions many academics look forward to every day. (I suppose I could be confident, for an additional charge.) Why is it trolling? Because the troll will never ever acknowledge his expectation that scientists (and science along with them) should thrive in a plutocracy as if it were a meritocracy [cf. Leiter, Brian, The Truth is Terrible (February 22, 2014). Daniel Came (ed.), Nietzsche on Morality and the Affirmation of Life (Oxford University Press, Forthcoming). Available at SSRN: http://ssrn.com/abstract=2099162 or http://dx.doi.org/10.2139/ssrn.2099162]

I happen to be returning to academia after leaving a non-academic job a few months ago. I spent the intervening months working an application with a friend. Over the past decade we have been attempting to solve a certain problem for ourselves. After dead end upon dead end, we have a prototype. Now, on the verge of re-joining the academic precariat, a potential customer has asked us for how much we would license our software. We'll see how that goes.

The probability of my landing a tenure-track position anywhere is less than the probability that the software venture succeeds (perhaps this isn't surprising, judging from my posts online here). One tires of playing zero-sum games for diminishing payoffs against people who should be your collaborators. This is the kind of the cost-benefit analysis one doesn't do explicitly that seems to underlie decisions to leave. (I am rational, according to a cost-benefit analysis I haven't done.)