Book-to-Market and Size Effect: Compensations for risks or outcomes of market inefficiencies
We employ the optimal orthogonal portfolio approach to investigate if the size and book-to-market effects in US data are related to risk factors beside the market risk. This method enables us to estimate the upper limit of the risk premium, due to observed as well as all possible unobserved factors, which can be derived from a linear asset pricing model. As a corollary, it is possible to divide th