I close out my visit this week with some thoughts on what we can learn from the analysis of sex in sport about who is a woman for purposes of different women's only spaces and opportunities; and whether these spaces and opportunities can continue to exist if they are not defined on the basis of sex.

Sex segregated spaces remain ubiquitous: bathrooms, locker rooms, dorm rooms, gyms, colleges, shelters, and prisons. Less obvious but still prevalent are sex-linked opportunities in education, employment, and medicine.

They exist as they do for a combination of reasons, some of which are just about tradition and dead or dormant stereotype; others, though, are about inherent differences and still-salient, actively operating stereotypes. Anti-discrimination law as applied to sex is designed to erode the former while retaining the latter. From RBG in VMI:

'Inherent differences' between men and women … remain a cause for celebration, but not for denigration of the members of either sex or for artificial constraints on an individual's opportunity. Sex classifications may be used to compensate women 'for particular economic disabilities [they have] suffered,' to promot[e] equal employment opportunity,' [and] to advance full development of the talent and capacities of our Nation's people. But such classifications may not be used, as they once were, to create or perpetuate the legal, social, and economic inferiority of women.

Women's sport is an example of a sex classification that is based in inherent differences and that is used to promote equal opportunity and the full development of females' talents and capacities. Thus, from Sex in Sport, "It would be a mistake to assume that [sex] can be read out of elite sport policy without causing a lot of important harm because biology determines competitiveness in this institutional space which is precisely about competition."

So is a STEM-related employment or educational opportunity set aside for females as a way to make up for past subordinations and exclusions and to grow their numbers going forward. Because females were subordinated within and excluded from these fields on the basis of sex and of false stereotypes about the cognitive aptitudes and capacities of females compared to males, it would be a mistake to assume that sex can be read out of the definition of "woman" for these empowerment opportunities if they are to be successful vehicles toward their designated ends.

In contexts like this, where the classifications continue to be necessary or useful as designed, it is right that females are privileged as against transgender women, or that there is a rebuttable presumption that "woman" for purposes of these spaces and opportunities means females. In these contexts, it is not right that if you identify as a woman you are a woman case closed. The classification "women" is not a catch-all or code for male gender non-conforming people. (Deconstructing sex can take you there if you let it.)

Rebuttable presumptions are, by definition, rebuttable. And so transgender girls and women are girls and women for purposes of these spaces and opportunities when their inclusion can be obtained without defeating the classification or category.

The way elite sport currently regulates women's events is again illustrative. Instead of categorically excluding male-bodied athletes from female events, it conditions their inclusion—and thus their classification as "women"—on dropping their T levels into the female range. This levels the playing field precisely according to the single trait that justifies the classification. Elite development sport also approaches the definition of "girls" this way.

(Education-based competitive sport can do the same for pubertal and post-pubertal males who identify as girls and women. See, e.g., the NCAA's eligibility rule. It could also consider unconditional inclusion of transgirls—no physical transition requirement—with offsets that ensure that no otherwise eligible females are themselves excluded as a result. Examples of offsets could be adding a spot to an otherwise numerically restricted team or event that will include a transgirl; and awarding two championships if a transgirl beats a female for the highest prize.

I would agree with the argument that offsets could dilute or at least change the value of the position, lane, or medal somewhat for both athletes; but this effect doesn't go to the core of the institutional mission, and it seems right to me that we should value inclusion in the education space more highly than any incidental discomfort that could arise from this policy choice. This equation would come out differently in the elite sport space since the signaling and economic values associated with being the visible single winner are part of the mission and more than merely incidental.)

In contrast, where inherent differences are not factually relevant, or where the false stereotypes about females derived from those differences have been (at least mostly) vanquished, there is no compelling reason to privilege females over transwomen. For me, these include girls' and women's public restrooms, locker rooms, dormitories, gyms, and prisons.

Exclusions in these categories are primarily justified by tradition and related concerns about privacy and safety. Safety for females in relation to male-bodied people is no small matter, but without a sound evidentiary basis for concluding that trans girls and women are more likely to be problems than other females—for example, more than "the mean girls who have always used [restrooms and related settings] as their safe bullying space"—we can't justify reading them out.

In contrast, physical privacy is a legitimate concern because reasonable expectations are based in community norms and sex-segregated public restrooms and like spaces remain the norm. But this just means that the switch is not cost-free, not that it is cost prohibitive. Having to retrofit restrooms to provide individual spaces won't affect institutional ends.

I do question whether women's only spaces and opportunities can continue lawfully to exist under current doctrine if they are not defined directly or indirectly on the basis of female sex. For example, can they continue to exist if, as some argue, it's no longer acceptable even to speak about female body parts when we define "woman" because doing so is "inherently reductionist and exclusive"? Can they continue to exist if, as the Obama Administration recommended, sex is erased from sex discrimination law and replaced by identity, defined as "[a]n individual's internal [but not necessarily biologically-based] sense of gender"?

I've heard the legal argument derived from these positions, that sex discrimination jurisprudence has evolved away from any (even indirect) focus on inherent differences; that it is now primarily focused on the mutable aspects of gender and the individual's autonomy related to their gender identity. That's not how I read the cases, in no small part because it would require conceiving of VMI as relic.

I'll end with this. If VMI were relic, if there were nothing left to sex in law, I'm not sure that identity—"which may be male, female, neither, or a combination of male and female, and which may be different from an individual's sex assigned at birth"—could automatically take its place, at least not as a protected class. Imagine the Olympic podium with three male-bodied athletes in the three medal positions in a women's event. If I'm right, set asides for "women" untethered from female biology would be difficult if not impossible to justify.