NUS academics distance themselves from study on civil servants' home purchases near unannounced MRT stations - CNA

The two professors say they have asked the authors to have their names removed from the paper’s acknowledgements.

This general view shows a private residential complex and the financial district in Singapore. (File photo: AFP/Roslan Rahman)

This audio is generated by an AI tool.

Abigail Ng 15 Sep 2026 10:51PM (Updated: 15 Sep 2026 11:55PM) Bookmark Bookmark Share WhatsApp Telegram Facebook Twitter Email LinkedIn Set CNA as your preferred source on Google Add CNA as a trusted source to help Google better understand and surface our content in search results. Read a summary of this article on FAST. Get bite-sized news via a newcards interface. Give it a try. Click here to return to FAST Tap here to return to FAST FAST SINGAPORE: Two National University of Singapore (NUS) professors Ivan Png and Jessica Pan said on Tuesday (Sep 15) they knew nothing of a working paper alleging "informed trading by civil servants" and have asked the authors to remove their names from its acknowledgements.

Two other NUS academics named in the paper, Sumit Agarwal and Wenlan Qian, referred CNA to the authors. A fifth NUS academic, Professor David Reeb, said he may have made a comment or asked a question when an earlier version of the paper was presented years ago.

Prof Png, who is a Distinguished Professor at NUS, told CNA he was puzzled to have been thanked in the paper, which examined property purchases by public officials near MRT stations whose locations had not yet been made public.

“I do not know the authors and did not know of their paper until a colleague referred me to the CNA report, following which I received a stream of WhatsApp messages from friends,” he said.

Prof Png, whose research interests include the economics of productivity and innovation, said he provided neither comments nor data for the study.

“Please remove my name from the acknowledgements,” he wrote to the lead author of the study in an email seen by CNA.

Prof Pan, who is vice-provost for graduate education at NUS, said her name appeared by "mistake". "I only found out about the paper today and have asked the authors to remove my name from the acknowledgements," she said.

CNA has contacted the authors of the paper: Tomasz Piskorski of Columbia University, Jian Zhang of the University of Hong Kong and Amit Seru and Chun Zhao of Stanford University.

CNA has also contacted all the other academics named in the acknowledgements to find out more about their input and involvement in the study.

Among these were four academics whom the authors said they had discussions with and “benefited immensely” from. They are University of Chicago’s Chang-Tai Hsieh and Luigi Zingales and Harvard University's Li Shengwu and Jesse Shapiro. 

Prof Hsieh, whose research interests are in areas such as growth and development, said he had discussed the paper at a conference previously. However, he questioned the results of the study. Among other things, he argued that since private housing is typically farther from the MRT stations compared with public housing, the "gain" from inside information on the locations of unannounced MRT stations would be “much smaller”.

Prof Zingales is a professor of entrepreneurship and finance at the University of Chicago, while Prof Shapiro is a professor of economics and business administration at Harvard. Prof Li, the estranged nephew of Senior Minister Lee Hsien Loong, is a professor of economics at Harvard. CNA has contacted them but has yet to receive replies. 

At least 16 other academics, including the five from NUS, were thanked by the authors for their “helpful comments”. Some of the research by these academics was also cited in the bibliography. 

The working paper, titled Do Social Norms Substitute for Enforcement? Evidence from Public Officials' Home Purchases in Singapore, was published this month by the National Bureau of Economic Research, a United States-based private nonprofit research organisation. 

The authors matched private property transactions from legal filings in Singapore against the Singapore Government Directory Interactive to identify civil servants, then examined purchases near unannounced MRT stations around announcement dates as a "proxy for access to privileged location information".

“We find clear evidence of informed trading by civil servants: purchase intensity near planned MRT stations is higher for civil servants than for matched controls, with the difference concentrated one to two years before public announcements,” they alleged.

The Public Service Division said on Monday that it was reviewing the paper's data and methodology.

"We take any integrity concerns extremely seriously. We are currently reviewing the data and methodology within the paper and will refer to CPIB (Corrupt Practices Investigation Bureau) if there is a material basis to do so," a spokesperson said.

CNA Games Guess Word Crack the word, one row at a time Buzzword Create words using the given letters Mini Sudoku Tiny puzzle, mighty brain teaser Mini Crossword Small grid, big challenge Word Search Spot as many words as you can Show More Show Less Related: Government reviewing study alleging civil servants 'disproportionately' bought homes near unannounced MRT stations HOW THE RESEARCH WAS CONDUCTEDThe authors wrote that they collected data from three sources to observe property trading activity of civil servants and other individuals, and integrated these datasets with property transaction records.

The first was the Singapore Government Directory Interactive, which lists the names and designations of civil servants. They collected data from six cohorts to reduce misclassification, since individuals may have left or just joined the public service at the time of a transaction. 

The second was the public register of the Council for Estate Agencies, and the third a proprietary dataset of demographic details and residential addresses for a large sample of Singapore residents as of 2013.

The authors also referred to filings of private property transactions with the Registry of Land Titles between January 1995 and December 2019.

The analysis focused on private housing, which the authors said offers easier access to anyone hoping to profit from privileged information, and where prices are expected to rise once station plans become public.

The researchers defined circular buffers around proposed stations and classified homes within them as "target" properties, using a 1km radius in the main analysis.

“For robustness, we also consider other cutoffs to separate houses that are more likely to experience price increases due to their proximity to the proposed MRT stations, from those that do not have such advantages,” they wrote.

To account for confounding factors, they created a control group matched closely to the civil servant group on age, gender, marital status and ethnicity.

The paper reported a "significant relative increase" in purchases near forthcoming MRT stations by civil servants in the one to two years before announcements.

Against the control group, the study estimated - based on statistical modelling - that civil servants would have made about 50 additional purchases near unannounced stations two years before plans were made public and 63 additional purchases one year before.

After announcements, civil servants and the control group exhibited similar trading behaviour, which the authors said pointed to pre-emptive buying in anticipation of the station announcements.

Civil servant buyers also held properties for slightly shorter periods, which the authors said suggested an economic motive. "However, these findings should be interpreted with caution due to the relatively small number of ex-post sales observations in our sample," they said.