Charles Blackorby, R. Robert Russell; The Morishima Elasticity of Substitution; Symmetry, Constancy, Separability, and its Relationship to the Hicks and Al

This paper suggests that the pure‐play technique can be used in conjunction with the capital asset pricing model to determine the cost of equity capital for the divisions of a multidivision firm. Since the beta for a division is unobservable in the marketplace, a proxy beta derived from a publicly traded firm whose operations are as similar as possible to the division in question is used as the measure of the division's systematic risk. To provide empirical support for using the pure‐play technique, a sample of multidivision firms and pure‐play associated with each division is examined. It is shown that an appropriately weighted average of the betas of the pure‐play firms closely approximates the beta of the multidivision firm.

This paper suggests that the pure-play technique can be used in conjunction with the capital asset pricing model to determine the cost of equity capital for the divisions of a multidivision firm. Since the beta for a division is unobservable in the marketplace, a proxy beta derived from a publicly traded firm whose operations are as similar as possible to the division in question is used as the measure of the division's systematic risk. To provide empirical support for using the pure-play technique, a sample of multidivision firms and pure-play associated with each division is examined. It is shown that an appropriately weighted average of the betas of the pure-play firms closely approximates the beta of the multidivision firm.

Russell Davidson, Richard Harris; Non-Convexities in Continuous Time Investment Theory, The Review of Economic Studies, Volume 48, Issue 2, 1 April 1981, Pages

Several procedures are proposed for testing the specification of an econometric model in the presence of one or more other models which purport to explain the same phenomenon.These procedures are shown to be closely related, but not identical, to the non-nested hypothesis tests recently proposed by Pesaran and Deaton [7], and to have similar asymptotic properties..They are remarkably simple both conceptually and computationally, and, unlike earlier techniques, they may be used to test against several alternative models simultaneously.Some empirical results are presented which suggest that the ability of the tests to reject false hypotheses is likely to be rather good in practice.