From The Washington Post:

In a forthcoming paper in the Academy of Management Journal, Michael Christian of the University of North Carolina’s Kenan-Flagler Business School and Aleksander Ellis of the University of Arizona’s Eller College of Management studied sleep-deprived nurses and students who’d pulled all-nighters in a sleep lab. They found that a lack of sleep led not just to poor performance on tasks that require “innovative thinking, risk analysis, and strategic planning”—though studies have shown all those to be true—but also to increased deviant and unethical behavior in both groups. Examples included rudeness, inappropriate responses and attempts to take more money than they’d earned.

These findings, while important, are not entirely surprising. I think it is obvious that basic human health is an essential part of setting the conditions for ethical behavior.