78,000 alumni in 167 countries. 4,161 attedning reunions, MBA & Executive Education alumni Alumni volunteers: 3,500 11,702 users of Alumni Career hub Class Notes: 18,000 Alumni mentions U.S. Competitiveness Survey: 9,750 Alumni respondents 1,100 Alumni Club Events Alumni Clubs: 108. 80 Geographically-based. 14 Affinity-based. 14 Affilated Harvard Clubs.