Eminent economist Dr K N Raj, who made significant contributions as an academic and planning expert since 1950s, died at a private hospital in Thiruanathapuram. Family sources said, 86 year old economist was undergoing treatment for old age-related problems for quite some time. He is survived by two sons. Held in high esteem by Jawaharlal Nehru, Raj was the co-author of the foreword to the first Five Year Plan. After working with the Reserve Bank of India and Planning Commission, he returned to teaching with the Economics department of Delhi University and also served as its Vice Chancellor later.