One of the oldest of these lies is that women are paid less than men for doing the same work. Like many other politically successful lies, it contains just enough of the truth to fool the gullible.
Women as a group do get paid less than men as a group. But not for doing the same work. Women average fewer annual hours of work than men. They work continuously for fewer years than men, since only women get pregnant, and most women are not prepared to instantly dump the baby on somebody else to raise.
Being a mother is not an incidental sideline, and being a single mother can be a major restriction on how much time can be put into a job, either in a year or over the years.
People like Hillary Clinton can simply grab a statistic about male-female income differences and run with it, since her purpose is not truth but votes. The real question however is whether, or to what extent, those income differences are due to employers paying women and men different wages for doing the very same jobs, for the very same amount of time.
We do not need to guess about such things. Many studies have been done over many years -- and they repeatedly show that women and men who work the very same hours in the very same jobs at the very same levels of skill and experience do not have the pay gaps that people like Hillary Clinton loudly denounce.
As far back as 1971, single women in their thirties who had worked continuously since high school earned slightly more than men of the same description. As far back as 1969, academic women who had never married earned more than academic men who had never married.
People who are looking for grievances are not going to be stopped by facts, especially if they are in politics. But where are our media pundits and our academic scholars? Mostly silent, either out of fear of being denounced as anti-women or because they have chosen to take sides rather than convey facts.
Nevertheless, there are enough scholars, including women economists, who have done enough honest studies over the years that there is no excuse for continuing to repeat a discredited lie, based on comparing apples and oranges. A book written by two women and titled "Women's Figures" shows the results when you compare women and men with comparable qualifications.
It is much the same story with black-white comparisons. More than 40 years ago, my own research turned up statistics on black and white professors who had Ph.D.s from equally high-ranked institutions in the same fields, and who had published the same number of articles.
When all these things were held constant, the black professors earned somewhat more than white professors. But, since all these things are not the same among black and white professors in general, there is a racial gap in pay that allows some to loudly denounce racial discrimination among academics.
Those who wish to check out my statistics can get a copy of my 1975 monograph, "Affirmative Action Reconsidered." It has not been updated because not all the same statistics will be released now. This is not unusual. Statistics that might undermine some other popular conclusions -- whether on affirmative action, global warming or whatever -- have been kept under wraps when other researchers tried to get them.
Too many people in the media and in academia abandon their roles as conduits for facts and take on the role of filterers of facts to promote social and political agendas.
In all too many educational institutions, from kindergartens to postgraduate university programs, students may never hear any facts that contradict the prevailing groupthink.
How many students taught by Keynesian economists will ever learn about the 1921 recession, when the Harding administration did nothing -- and unemployment dropped steeply as the economy recovered on its own?
There are many reasons why old lies, refuted long ago, are still heard every election year, and in all too many other years.