Size and stock market integration: a study of Canadian firms

Abstract

In this article the restrictions imposed on excess returns by a dynamic optimization model are tested on stock market data from the Toronto Stock Exchange (TSE), from which ten size-portfolios have been formed. The model implies that all excess returns should move proportionately if assets are perfectly integrated. The restriction that all size portfolios are governed by one single latent variable is rejected over the sample period 1961–2002. It is established that this rejection is due to the presence of the smallest size portfolio, especially during the second half of the sample period. The uncertainties of the late 1980s and 1990s appear to require the presence of a second latent variable. No definite conclusions can be drawn regarding these sources of risk even if the return on the market portfolio and exchange rate fluctuations play an important role.