It's more than that, as far as money is concerned. The schools collaborate on research projects and certain professors and research departments at one school will lend their names with other schools for the acquisition of grant money. The big names all help in those grant dollars. A poster on the Michigan blog
MGoBlog (about Johns Hopkins joining the Big 10 for Lacrosse) puts it better than I can:
As for admin dealings, check out the CiC. It contains every B1G member and UChicago, as they used to be a member prior to cutting all their sports. The CiC is amazingly stable and amazingly good at getting grants. A lot of schools would kill to get a seat at that table (word is Notre Dame's faculty foamed at the mouth when ND turned down a spot in the Big Ten). The CiC ensures the research efforts of the B1G are coordinated. When one CiC school goes after a big grant, the others help them out. That can range from getting big name profs at various schools to combined their star power together on one grant to lobbying the Congressional reps in the home states of the various schools to help the schools get the grant (Senators calling up the CDC and encouraging them to strongly consider Michigan's application for money, that sort of thing). This is a big business and athletics is nothing compared to it. As I mentioned, Michigan's hospital system normally has billions in active grants, compared to the 60 to 80 million that athletics makes every year. At one point I worked for a research lab that had 20 people and 70 million in active grants. The two profs who ran the lab had a better revenue stream than Brandon thanks to the NIH and CDC throwing money at us like we were the only hot stripper at the club.
You can also use these kind of ties to develop areas you don't have. Say for example some random B1G school wants to build a kick ass cancer center. They start some joint projects with Michigan, where Michigan's name is used to get the grant, but it gets the other school some funds to buy supplies, hire faculty/postdocs/, and so on and so forth. Michigan of course also gets a cut of the pie. Eventually the other school is strong enough to stand on its own. Normally this is also coordinated to supplment current CiC programs as opposed to competing.
If JH also affilates with the CiC at some level, which doesn't seem unreasonable since it offers perks ranging from library sharing to grant cooperation, that is a huge win for us. It is also while I'm strong against Maryland and Rutgers joining. While they bring NJ and Maryland Congressional reps into play for lobbying, they're a net drag everywhere else and a fiscal burden on both the sports and CiC sides. The academics welcomed Nebraska because they had a solid library (meaning they won't always be asking for our books via interlibrary loan) and a strong rep with various federal agencies that give out grants for things like farming, national park management, etc. Rutgers and Maryland just suck in terms of having a massive of research grants. Moving in JH as a partner instead of a competitor for NIH and CDC grants is a nice win.
Again, this is a random poster on an athletics blog, but it's pretty accurate from what my knowledge is. Having research giants Chicago, Wisconsin, Michigan, Northwestern, and potentially Johns Hopkins (they have joined the Big 10 for Lacrosse, but haven't decided if they are joining the CiC yet) in your corner when applying for grant money goes a very long ways in earning those grants. I understand that The ACC and The SEC are setting something similar up, but it will take a very long time to get on equal footing, if they do at all.
This is why AAU membership is important to the Big 10. If an appropriations committee sees a grant application with an AAU school on it, they don't have to research as deep whether the monies are going to a well run lab or not. The AAU designation helps in that regard (as does the Carnegie designation UConn holds). It all boils down to the CiC. I have stated this before, but the Big 10 is a collections of highly regarded research schools that play sports against each other while cooperating academically.
When I started following this whole mess back in 2010 (with Frank the Tanks post of Texas), big names were all I cared about joining the Big 10. Now, it's all about fit. Would Texas fit? Absolutely! Oklahoma? Yes (they have the Carnegie designation as well). ND? Nope, they want too many special privileges. UConn would be a great fit. I do believe that UConn will find a home somewhere, good luck!