Following up on "A Congressional Insider Trading ETF (SCUM)".
From the Atlantic:
...A few years ago, after the Center for Responsive Politics made congressional disclosure forms available in an easily searchable data set, two graduate students in Harvard’s political-science department decided to revisit the question for the new millennium. Andrew Eggers and Jens Hainmueller, now assistant professors at the London School of Economics and MIT, respectively, had become interested in the emerging literature on whether politicians benefit financially from holding office, and they were just finishing their first paper, which used probate data to look at that question in the United Kingdom. (Answer: yes, at least if they were Tories in the House of Commons between 1950 and 1970.)HT: Carney at NetNet
They eagerly attacked the U.S. data. Both of them got a big surprise. Their data, which covered 2004 through 2008, didn’t show Congress outperforming the market by 12 percent. In fact, they didn’t show it outperforming the market at all. For the five years they studied, Congress actually underperformed the market by 2 to 3 percent annually. On average, Congress did worse than an index fund, and about as well as your average stock-picking granny. If Congress was indeed trading on inside information in the late 1990s, it seemed to have stopped.
But, if all the data are right, why would congressional stock-picking have changed so much? That’s “the one fact that we cannot 100 percent nail down,” says Hainmueller ruefully, especially since Ziobrowski et al. haven’t released their painfully assembled data set. One of the papers could be wrong, of course, but it’s hard to adjudicate that when one group hasn’t released its data and the other’s paper hasn’t yet been published in a peer-reviewed journal—and anyway, neither group is openly disputing the other’s results. Still, Eggers and Hainmueller’s difficulty in explaining the difference may make it harder for them to get their own results published....MORE