In other cases, there are compelling reasons for women to endure the work-life challenges their companies pose, such as economic necessity, the inability to do a particular job outside of big institutions or because of the need to gain experience and credentials.

FORBES: Don't Lean In. Walk Out.

Water, something we take for granted here in the U.S., is a life-or-death necessity in some disadvantaged countries in the world.

FORBES: Tapping the Well of Philanthropy: Scott Harrison and Charity Water

The search for profit, they argue, may be a regrettable necessity in the modern world, a sad fact of life if there is to be any private enterprise.

ECONOMIST: Capitalism and ethics