He wrote several books and published many articles on issues such as democracy, development, decentralization and economy of Kerala and India.
Oommen developed an accurate and scientific curriculum for the departments of economics in various universities of Kerala and also conducted financial planning for African countries such as Botswana.
[1] Oommen, who has been appointed economic adviser to the Botswana government, has publicly criticized the country's central budget for generously subsidizing rich businessmen.
[8] He wrote more than 30 books in Malayalam and English and published 400 papers which collectively form a comprehensive economic history of Kerala's last 7 decades.
[7] Oommen's 2008 study on the role of the Kutumbashree movement in uplifting the social status of women in Kerala is important in this regard.