Haas Business Student Association (HBSA) | 2,531 followers on LinkedIn. The Haas Business Student Association is the undergraduate student government of UC Berkeley’s Haas School of Business. | Haas Business Student Association is the primary student government of the Haas School of Business. We are in charge of campus wide events, workshops, and more! There are many ways to get involved with HBSA including attending events and getting involved with a committee of your choice.