Columbia University and Barnard College are two independent institutions with a long shared history and a close, somewhat unique, relationship that often leads to misconceptions and misinformation. The relationship between the institutions is defined by an intercorporate agreement reached by the schools when Columbia College began admitting female students, creating a potential redundancy between the schools. The agreement has been ammended and renewed every certain number of years.
Despite the ambiguity, which has prompted endless rumination from all quarters, informed and (more often than not) uninformed, the school is for all intents and purposes part of the same college life as the Columbia schools. In day-to-day affairs the lines between the schools, endlessly argued over in theory, are in fact almost non-existent.
The Intercorporate Agreement between the schools has a number of provisions.
Though Barnard College has its own faculty, the tenuring process requires that Barnard faculty appointees be reviewed by their peers at Columbia in addition to Barnard.
As per the intercorporate agreement between the institutions, Barnard college degrees are officially granted by the Trustees of Columbia University, the same body that grants degrees to all Columbia students. This despite Barnard's status as an affiliate as opposed to an integrated undergraduate school. This often the basis of the claim that Barnard students are Columbia students too, when in fact it's just part of the agreement between the schools.
Barnard College pays Columbia University for access to Columbia's Library system, allowing its students and faculty the advantages of access to the resources of a major research institution.
The schools have nearly complete cross-registration, with the only exceptions applying to certain Core requirements at both schools. Registration for Columbia students is almost seamless, with Barnard departments courses listed on the Columbia Course Directory, and registerable through the same process as Columbia courses on SSOL.
The agreement between the schools requires a payment for the balance of credit flow. Initially Columbia expected this to be a source of income as it's much greater range of course selection would result in more Barnard students taking Columbia courses rather than vice versa. In recent years that trend has shifted, with more Columbia students taking Barnard courses rather than the other way around, meaning that Columbia has to pay Barnard an annual fee to pay for the imbalance. This can be attributed to Barnard's decision to develop departments that have no counterpart across the street, such as Urban Studies, Women's Studies, and the undergraduate Theater and Dance programs.
Barnard pays Columbia for access to power and utilities and access to other facilities that it otherwise would have to provide for itself.
Athletics - The Consortium
As part of an NCAA approved consortium, Barnard does not maintain an athletics program of its own, but instead women athletes from Barnard compete on University-wide (i.e. "Columbia") athletic teams. There are 3 such consortiums in the nation (such a the one between the 5 colleges of Claremont Mckenna), and Columbia-Barnard's is the only one in Division I. Barnard athletes figure prominently on a number of teams, including Archery.
Whether or not Barnard is an 'Ivy League' school depends on the interpretation of the term. The Ivy League is an NCAA Division I athletics conference with 8 member schools. Though Barnard itself is not affiliated with the league, as per the consortium agreement, Barnard athletes play on Columbia teams. As such, Barnard is essentially a league member, though only through its connection to Columbia.
As an academic institution, the claim is more tenuous. Especially since Barnard is traditionally held to be a member of the 'Seven Sisters' colleges.
Barnard's single-sex admissions policy is an issue of some controversy on Columbia's campus. Some consider it to be outmoded and even sexist. The Barnard administration, as well as the Barnard student population, believe that its single-sex policy is necessary to the educational mission and general college environment. Generally they point to both the continual existence of sexism within society as well as data that suggests that at least some women work better and are more likely to succeed in general when they are educated at all female colleges. Barnard has a unique relationship with its parent Ivy compared to the other Seven Sisters colleges. For example, before Harvard went coed, Radcliffe College was a separate college affiliated with Harvard. Soon after Harvard began accepting women, Radcliffe was subsumed into Harvard College. Barnard has long been concerned about losing its individual identity as a college, as Radcliffe did, and as it most certainly would if it integrated with Columbia.
Barnard students are given email address at both barnard.edu and columbia.edu. There are some who believe this is unfair because Barnard students are only affiliates of the school. However, most would point out this is policy is for academic simplicity. This way, teachers can just email all their students at their Columbia email addresses using Courseworks, instead of having to figure out which students have Columbia email addresses and which have Barnard email addresses.
Residence hall swipe access
Barnard and CC/SEAS undergrads have historically not had swipe access to each others residence halls. Students on both sides of the street have varying opinions on this policy. Some Barnard students believe they should have access to Columbia undergraduate dorms, but CC/SEAS undergraduates should not have access to the Barnard dorms because only girls (or mostly girls) live in these dorms and thus Barnard dorms have extra security risks. Other students from both CC/SEAS and Barnard believe that neither of the two undergraduate populations should have access to the other's dorms. The two student populations belong to separate schools, these students argue, and thus each should only have access to their own dorms and the resources therein. Finally there are students, both from Barnard and CC/SEAS, who believe that all the undergraduates within Columbia university should have access to each others dorms. Students of this view generally argue that the two student populations are not really separate and that it is inconvenient for both Barnard and CC/SEAS students to not be able to swipe into each others dorms. Recently there was a campaign for "Flash Access" in which Barnard/CC/SEAS undergraduates would be able to sign a special security contract and then would be able to themselves sign into the other schools dorm. Barnard and Columbia do give swipe access to students who chose their housing through the Barnard/Columbia room selection process.