Thin‐Trading Effects in Beta: Bias v. Estimation Error
Year: 2008
Type: article
Abstract: : Two regression coefficients often used in Finance, the Scholes‐Williams (1977) quasi‐multiperiod ‘thin‐trading’ beta and the Hansen‐Hodrick (1980) overlapping‐periods regression coefficient, can both be written as instrumental‐variables estimators. Competitors are Dimson's beta and the Hansen‐Hodrick original OLS beta. We check the performance of all these estimators and the validity of the t‐tests in small and medium samples, in and outside their stated assumptions, and we report their performances in a hedge‐fund style portfolio‐management application. In all experiments as well as in the real‐data estimates, less bias comes at the cost of a higher standard error. Our hedge‐portfolio experiment shows that the safest procedure even is to simply match by size and industry; any estimation just adds noise. There is a clear relation between portfolio variance and the variance of the beta estimator used in market‐neutralizing the portfolio, dwarfing the beneficial effect of bias.
Authors: Piet Sercu, Martina Vandebroek, Tom Vinaimont
Institutions: City University of Hong Kong, KU Leuven
Language: English
Subfield: Finance
Domain: Social Sciences
Open Access status: green
OpenAlex ID: W3206642017