Sanjay Kumar is Professor and Co-Director of Lokniti, a Research Programme at the Centre for the Study of Developing Societies. His core area of research is Electoral Politics, but using survey method as research tool he has been engaged in conducting research on very wide range of themes-Indian Youth, State of Democracy in South Asia, State of Indian Farmers, Slums of Delhi and Electoral Violence.  

He has published widely, written several books, edited volumes, contributed chapters for several edited volumes, published articles in various national and international research journals. His most recent book is Elections in India: An Overview. His other publications include Post Mandal Politics in Bihar: Changing Electoral Patterns, Changing Electoral Politics in Delhi: From Caste to Class, (with Praveen Rai) Measuring Voting Behaviour in India, Women Voters in Indian Elections: Changing Trends and Emerging Patterns, Youth in India: Aspirations, Attitudes, Anxieties,  Indian Youth and Electoral Politics: An Emerging Engagement, (with Suhas Palshkar and Sanjay Lodha) Electoral Politics in India: Resurgence of the Bhartiya Janata Party, (With Christophe Jaffrelot) Rise of the Plebeians? The Changing Face of Indian Legislative Assemblies and (with Peter R deSouza and Sandeep Shastri) Indian Youth in a Transforming World: Attitudes and Perceptions.  

Besides his academic writing he writes regularly for both national and regional newspapers, both in English and Hindi languages. His articles are published regularly in The Hindu, Indian Express, Asian Age, Deccan Chronicles, Dainik Bhaskar, Rajasthan Patrika and The Mint. He is also a well know face on Indian Television as Psephologist and Political Commentator. He has also been an international election observer in many countries.