Conditional CAPM: Time-varying Betas in the Brazilian Market

Main Article Content

Frances Fischberg Blank
Carlos Patricio Samanez
Tara Keshar Nanda Baidya
Fernando Antonio Lucena Aiube

Abstract

The conditional CAPM is characterized by time-varying market beta. Based on state-space models approach, beta behavior can be modeled as a stochastic process dependent on conditioning variables related to business cycle and estimated using Kalman filter. This paper studies alternative models for portfolios sorted by size and book-to-market ratio in the Brazilian stock market and compares their adjustment to data. Asset pricing tests based on time-series and cross-sectional approaches are also implemented. A random walk process combined with conditioning variables is the preferred model, reducing pricing errors compared to unconditional CAPM, but the errors are still significant. Cross-sectional test show that book-to-market ratio becomes less relevant, but past returns still capture cross-section variation.

Article Details

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Long Paper
Author Biographies

Frances Fischberg Blank, Pontifícia Universidade Católica do Rio de Janeiro - PUC-Rio

Departamento de Engenharia Industrial Rua Marquês de São Vicente, 225 – CEP 22451-900, Rio de Janeiro, RJ, Brasil tel: (21) 99766-2281

Carlos Patricio Samanez, Pontifícia Universidade Católica do Rio de Janeiro - PUC-Rio

Departamento de Engenharia Industrial Rua Marquês de São Vicente, 225 – CEP 22451-900, Rio de Janeiro, RJ, Brasil tel: (21) 3527-1284

Tara Keshar Nanda Baidya, UNIGRANRIO

Programa de Pós-Graduação em Administração - PPGA, Mestrado e Doutorado em Administração & Escola de Ciência e Tecnologia Rua Professor José de Souza Herdy, 1160 – CEP: 25071-202, Duque de Caxias, RJ, Brasil Tel: (21) 2531-8804 / 2531-8268

Fernando Antonio Lucena Aiube, Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) & Petrobras

Departamento de Engenharia Industrial Rua Marquês de São Vicente, 225 – CEP 22451-900, Rio de Janeiro, RJ, Brasil tel: (21) 3527-1284