A net beta test of asset pricing models

While many recent empirical studies of the CAPM have used conditional beta tests, this technique has recently been shown to have several weaknesses. Here we introduce a new, more robust, net beta test which shares a number of characteristics with conditional beta tests. The method is extended to the multi-factor case when there are mimicking portfolios of assets for the underlying factors, including the Fama-French three-factor model. We demonstrate theoretically, by simulation and using market data that the net beta estimators have lower standard errors than those generated by the standard Fama-MacBeth test.