Sloan School of Management
Cambridge, MA 02142
Institutional Affiliation: Massachusetts Institute of Technology
NBER Working Papers and Publications
|January 2013||Which News Moves Stock Prices? A Textual Analysis|
with , , : w18725
A basic tenet of financial economics is that asset prices change in response to unexpected fundamental information. Since Roll's (1988) provocative presidential address that showed little relation between stock prices and news, however, the finance literature has had limited success reversing this finding. This paper revisits this topic in a novel way. Using advancements in the area of textual analysis, we are better able to identify relevant news, both by type and by tone. Once news is correctly identified in this manner, there is considerably more evidence of a strong relationship between stock price changes and information. For example, market model R-squareds are no longer the same on news versus no news days (i.e., Roll's (1988) infamous result), but now are 16% versus 33%; variance r...
|July 2010||Trading Complex Assets|
with : w16187
We perform an experimental study of complexity to assess its effect on trading behavior, price volatility, liquidity, and trade efficiency. Subjects were asked to deduce the value of a particular asset from information they were given about the composition and price of several portfolios. Following that, subjects traded with each other anonymously in a well-defined, simple bargaining process. Portfolio problems ranged from requiring simple analysis to more complicated computation. Complexity altered subjects' bidding strategies, decreased liquidity, increased price volatility, and decreased trade efficiency. Female subjects were affected more by complexity (e.g., lower trade frequency), although they achieved higher payoffs in the complex treatment. Our analysis suggests that complexity ma...
Published: “Trading Complex Assets” (with Shimon Kogan and Richard Lowery). Journal of Finance 68: 1937-1960, 2013.
|June 2009||Is Investor Rationality Time Varying? Evidence from the Mutual Fund Industry|
with , , : w15038
We provide new empirical evidence suggesting that the marginal investor in mutual funds behaves differently across market conditions. If the marginal investor allocates capital across mutual funds rationally, then the relative performance of funds should be unpredictable. We find however that relative fund performance is predictable after periods of high market returns but not after periods of low market returns. The asymmetric predictability in performance we document cannot be explained by time-varying differences in transaction costs or style exposures between funds, or by sample selection. Consistent with the hypothesis that the asymmetric predictability in performance may be driven by unsophisticated investors' mistakes when allocating capital, we document that performance predictabil...