[a] Haas was born to a Jewish family in San Francisco, the son of Elise (née Stern) and Walter A.

[7] Haas was the owner of the Oakland Athletics baseball club, acquiring the team from Charles O. Finley in August 1980 for less than $13 million.

[8][10] Under Haas' ownership, the Athletics won five American League West Division titles (the first in 1981 and the last in 1992, advancing to three consecutive World Series between 1988 and 1990, defeating the cross-bay rival San Francisco Giants in 1989 in a sweep marred only by the infamous Loma Prieta earthquake).

Haas would accept the Commissioner's Trophy on behalf of himself, the players, and Tony LaRussa, who won his first world championship.

He was also involved in other nonprofit institutions such as the Hunter’s Point Boys’ Club and the San Francisco Chronicle’s Season of Sharing Fund.