 In 1974 he joined the newly founded Centre for Studies in Social Sciences, Calcutta, which went on to become one of the most productive and globally famous research institutions in India.Bagchi has specialised in the history of Indian banking and finance, and acted as Official Historian of the State Bank of India (SBI) from 1976 to 1998; he played a leading role in ensuring that the unique archives of SBI are preserved for posterity.After retiring as Reserve Bank of India professor from the Centre for Studies in Social Sciences, Calcutta in 2001, he became the founder-director of the Institute of Development Studies, Kolkata, a multidisciplinary centre of excellence in the social sciences, which is affiliated with the University of Calcutta, and is promoted by the government of West Bengal.