Thomas Sowell: The grand fallacy: "People without the slightest knowledge of economics or the slightest experience running a business will boldly assert that women are paid only 75 percent -- or some other percent -- of what men make for doing exactly the same work.
Think about it. If an employer could hire four women for the price of hiring three men, why would he ever hire men at all?
Even if the employer was the world's biggest sexist, he could still not survive in business if his competitors were getting one-third more output from their employees for the same money."