Over the last decade or so, a confused idea that started in the nonprofit sector has gradually seeped into liberal discourse more generally. According to this idea, “equality” is bad or inadequate and what we need instead is something called “equity.”

Bernie Sanders was asked to explain the difference between them on Real Time this weekend and he didn’t really know what to say.

On @billmaher @CNN Tonight, @SenSanders did not know the difference between equality and equity, and yet the federal govt spending billions of dollars on equity training right now in every single federal agency. If a U.S. Sen doesn’t know the diff why are we spending that $? pic.twitter.com/KAaUXjBUZB

— Brian Doherty (@BDOH) March 4, 2023

This exchange lit up both conservatives and liberals. Conservatives lit up because they associate the word “equity” with Diversity, Equity, and Inclusion (DEI) trainings, which have proliferated across the corporate sector despite being pretty obviously stupid. Liberals lit up because they have adopted this word very vigorously and think it reflects badly on Sanders that he doesn’t have a spiel about it ready to go.

In the meta-discourse about the exchange, the debate has devolved into whether it is good or bad for politicians to use the linguistic innovations of the nonprofit or academic sectors, which at this point is a fairly well-rehearsed kind of affair where one side says that language is very key to oppressed peoples and the other side says that it is not key to them and alienates others.

But missing in this discourse is an actual answer to the question presented to Sanders: How does equity differ from equality?

In my early twenties, I spent much of my time reading and thinking about egalitarian political philosophy of both leftist and liberal varieties. And so when people started saying they were against “equality” but for “equity” shortly after that, I was well-positioned to integrate that claim into my understanding of existing egalitarian philosophy. And it was clear then as it is now that “equity” is being used to mean “equality of the correct unit of equality.”

To understand what I mean, let’s look at the foundational philosophical text of the “equity” revolution, which is actually just a two-panel cartoon meme.

In the “equality” panel, there is an equal distribution of boxes. In the “equity” panel, there is an equal distribution of sight lines. So it’s equality in both cases. To the extent that you are supposed to glean anything from the panel, it’s that, in the case of watching a baseball game, the correct unit of equality is sight lines not boxes.

At times, people try to boil this move down into just being a linguistically novel way to advocate for equality of outcomes over equality of opportunity. Proponents of “equity” consistently reject this simplification and, from what I can tell, those proponents are actually correct to reject it. “Equity” is not used to promote any particular unit of equality — whether outcomes, opportunities, boxes, sight lines, luck-adjusted outcomes, primary goods, income, wealth, or capabilities — but is instead a word that you invoke any time you object to the unit of equality someone else is using, regardless of what, if any, your preferred alternative unit of equality is.

A good case of this I saw recently was when, back in COVID days, the United States Postal Service (USPS) announced that it would be sending four COVID tests to each household in the mail. In a wildly popular tweet, a prominent “equity” advocate said that this was a perfect case to illustrate why “equality” is so inferior to “equity.” They elaborated that this program was “equal” because it sent the same number of COVID tests to each household but “inequitable” because different households have different numbers of people in them.

Of course, in more natural language where we don’t keep flipping back and forth between two words, what you would say, using just “equality,” is that the USPS program was equal on a per-household basis but unequal on a per-person basis, and that, in the case of distributing diagnostic tests, the per-person basis is the more appropriate one.

The point that whether something is considered “equal” or not is sensitive to what unit you use to measure equality is a pretty introductory concept in egalitarian thought. The Stanford Encyclopedia of Philosophy spends a huge chunk of its article on egalitarianism detailing the issue. In egalitarian thought, it’s generally referred to as the “equality of what” question, which is also the title of a famous Amartya Sen lecture on the question from 1979. In the lecture, Sen rejects “utility” and Rawlsian “primary goods” in favor of his own “basic capabilities” as the best unit of equality.

If the advocates of “equity” had a specific unit of equality that they were consistently pushing, then it would be fairly easy to explain what it is. You’d just say “equity means equality of X” as contrasted with other units of equality like Senian capabilities, Rawlsian primary goods, Dworkinian resources, etc.

But advocates of “equity” instead use the word to mean “equality of the correct unit of equality” where “the correct unit of equality” changes speaker to speaker and case to case and is sometimes not actually defined at all. And given this reality, it’s genuinely difficult to answer the question, “How does equity differ from equality?” when asked in the general way Bill Maher did.

As a final note, I will say that there is one thing that slightly annoys me about the meta-discourse on this exchange that focuses on the value of academic language. This is a worthwhile discourse generally, but it actually has it slightly backward in this case. The academic discourse on egalitarianism is both interesting and clear in tackling the “equality of what” question. What we have with “equity” is nonacademics who clearly have no familiarity with the relevant academic discourse coming up with a half-baked and badly theorized version of it.