Sure but that's not really related to what I'm talking about. A top 5 MBA obviously possesses an extremely high capability to find alternative employment if they quit their current job (for ethical or other reasons.) Yet we would never expect those graduates to be more ethical than the average low-demand worker.

What you're saying seems akin to saying that a Stanford MBA is in less demand than the average programmer. (1) I think that's wrong. (2) It's really avoiding the point which his that being in demand doesn't really imply that those individuals will act more ethically.

One way of measuring demand is to look at how long the average job search lasts. In that context Stanford MBA's often take a rather long time between jobs as in 12-18 months is not uncommon.

Various euphemisms exist, like taking a break or the ever popular consulting. But, getting a job in school or being poached while employed is the happy path. Get off that path and it can be very hard to get back.

PS: I don't think demand changes the average much, but it's often outliers that stand up in the first place. So, I do think demand is meaningful as it reduces the burden of ethical behavior which impacts people at the edge.