NUS professors seek removal from study alleging civil servants traded on MRT tips
Two NUS professors have asked to be removed from the acknowledgements of a working paper alleging civil servants bought homes near unannounced MRT stations. The paper, published by the National Bureau of Economic Research, claims evidence of informed trading by public officials. The Public Service D
SINGAPORE: Two National University of Singapore (NUS) professors, Ivan Png and Jessica Pan, said on Tuesday (Sep 15) that they had no knowledge of a working paper alleging "informed trading by civil servants" and have asked the authors to remove their names from its acknowledgements.
Prof Png, 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," he said, adding that he provided neither comments nor data for the study. Prof Pan, vice-provost for graduate education at NUS, said her name appeared by "mistake" and she had asked the authors to remove it.
Two other NUS academics named in the paper, Sumit Agarwal and Wenlan Qian, referred CNA to the authors. A fifth, Professor David Reeb, said he may have made a comment or asked a question when an earlier version was presented years ago. CNA has contacted the paper's authors — Tomasz Piskorski of Columbia University, Jian Zhang of the University of Hong Kong, and Amit Seru and Chun Zhao of Stanford University — as well as other academics named in the acknowledgements, including University of Chicago's Chang-Tai Hsieh and Luigi Zingales, and Harvard University's Li Shengwu and Jesse Shapiro. Prof Hsieh questioned the results, arguing that since private housing is typically farther from MRT stations than public housing, the "gain" from inside information on unannounced station locations would be "much smaller".
The working paper, titled Do Social Norms Substitute for Enforcement? Evidence from Public Officials' Home Purchases in Singapore, was published this month by the Massachusetts-based National Bureau of Economic Research. The authors matched private property transactions from legal filings 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". They alleged: "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."
The paper reported a "significant relative increase" in purchases near forthcoming MRT stations by civil servants in the one to two years before announcements, with about 50 additional purchases two years before and 63 additional purchases one year before. "A back-of-the-envelope calculation yields approximately S$138 million (US$108 million) in gross target-property acquisition value associated with the excess pre-announcement purchases," it said. People identified as relatives of civil servants made 108 additional purchases up to three years ahead, worth about S$132 million. The paper put the additional annual return on such a purchase at nearly S$147,000.
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 if there is a material basis to do so," a spokesperson said.
