Joint research unit 7235

Is the Market Portfolio Efficient? A New Test to Revisit the Roll (1977) versus Levy and Roll (2010) Controversy

Marie Brière, Kim Oosterlinck, Ariane Szafarz, Valérie Mignon, Bastien Drut

Levy and Roll (Review of Financial Studies, 2010) have recently revived the debate related to the market portfolio’s efficiency suggesting that it may be mean-variance efficient after all. This paper develops an alternative test of portfolio mean-variance efficiency based on the realistic assumption that all assets are risky. The test is based on the vertical distance of a portfolio from the efficient frontier. Monte Carlo simulations show that our test outperforms the previous mean-variance efficiency tests for large samples since it produces smaller size distortions for comparable power. Our empirical application to the US equity market highlights that the market portfolio is not mean-variance efficient, and so invalidates the zerobeta CAPM.

AGENDA

Monday 23 May 2022

Law, Institutions and Economics in Nanterre (LIEN)

Clara Jean (Grenoble Ecole de Management)

The Value of Your Data: Privacy and Personal Data Exchange Networks

Monday 23 May 2022

Law, Institutions and Economics in Nanterre (LINK)

Clara Jean (Grenoble Ecole de Management)

The Value of Your Data: Privacy and Personal Data Exchange Networks

Monday 30 May 2022

Law, Institutions and Economics in Nanterre (LIEN)

Antoine Dubus (ETH Zurich)

Salle G110

Data Driven Mergers and Acquisitions with Information Synergies

Monday 30 May 2022

Law, Institutions and Economics in Nanterre (LINK)

Antoine Dubus (ETH Zurich)

Salle G110

Data Driven Mergers and Acquisitions with Information Synergies

Tuesday 31 May 2022

Series of Webinars on Economics of Environment, Energy and Transport (SWEEET)

Juan Pablo Montero (PUC)

TBA

Tuesday 31 May 2022

Series of Webinars on Economics of Environment, Energy and Transport (SWEEET)

Juan Pablo Montero (PUC)

TBA

Thursday 9 June 2022

Lunch

Rémi Generoso

TBA

Thursday 9 June 2022

Lunch

Rémi Generoso

TBA

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