Png is the author of Managerial Economics, which has been translated into Chinese and Korean. Managerial Economics is written, "in simple, accessible style, the text-book presents the essentials of managerial economics." The book has been revised four times, with the fifth English edition published by Routledge. In the early part of his career, Png's carried out applied theoretical research, studying the economics of litigation and enforcement, and showing several notable results with Dilip Mookherjee. In mid-career, he switched to empirical methods. Recent research has focused on the economics of innovation, particularly, trade secrecy and tracking professional mobility, and the economics of productivity, for which he received funding from the Social Sciences Research Council.
University Management
In 2000, Png was appointed the Dean of the School of Computing at the National University of Singapore. In the following year, the National University of Singapore re-organized management along U.S. lines, with the Chief Academic Officer taking the title of Provost. Png was the first incumbent in the post of Vice Provost for Graduate and Undergraduate Education. As Vice Provost, he oversaw the development of a University-wide course bidding system to resolve persistent complaints about access to high-demand courses, brought back semester examinations from off-campus sites to campus, and brought forward the University graduation ceremonies from September to July.
Policy
Png was a nominated MP from 2005 to 2006. His first asked the Minister for Education to report examination results by family income and not race. In October 2005, Png unsuccessfully moved an to reduce record-keeping to five years from seven years. Subsequently, the government passed an to reduce record keeping across multiple laws to five years. In November 2005, he queried whether the revenue pool between Singapore Airlines and Malaysian Airlines on the Kuala Lumpur - Singapore air route restricted competition. During the 2006 budget debate, he famously christened the Golden Mile Shopping Centre as a "". In a series of opinion articles in the Singapore and Malaysian media, he advocated that environmental laws be extended to outlaw trans-boundary emissions.
Other activities
Png was a Reserve Officer in the Singapore Armed Forces, Third Division, leaving the service with the rank of Captain.