| Abstract: | Virtually all empirical tests of the Capital Asset Pricing Model have assumed (usually implicitly) that returns of some New York Stock Exchange index measure the returns of the “market factor” without error. However, recent theoretical developments suggest that this assumption may be inappropriate. In this effort, an obverse tack is adopted — the asset pricing model is assumed correct and attention is focused on the impacts of incorrect specification of market returns. A simple errors-in-variables econometric technique is used to reevaluate the oft-cited study of Black, Jensen, and Scholes. The conclusion is reached that incorrect measurement of the market is itself an onerous and unreconciled problem which adds marked bias to tests of asset pricing mechanisms. |
