The market impact of short-sale constraints

Abstract: The thesis addresses two areas of research within financial economics: empirical asset pricing and the borderline area between finance and economics with emphasis on econometrical methods. The empirical asset pricing section considers the effects of short-sale constraints on both the stock market as well as the derivatives market. Many arbitrage relations in the economy are intimately tied to the possibility to go short. One such arbitrage relation is the put-call-parity (PCP) relation that dictates a pricing relation between several derivative instruments and their underlying assets. During the latter part of the 1980s stock options could be traded in Sweden, while at the same time shorting was not permitted. The main contribution of the paper is to show that this shorting prohibition indeed implied larger deviations from PCP. Furthermore, this effect is only relevant for firms with stocks that were not shortable abroad, as firms with stocks shortable abroad did not show any deviations from PCP. The second paper investigates the asymmetries found in the momentum effect. Previous studies have found that the momentum effect is mostly due to the fact that a portfolio of loser firms tend to continue perform poorly, rather than because a portfolio of winner firms continue to do well. The explanation for this phenomenon investigated in the paper is based on the theoretical work by Diamond and Verrecchia (1985). In this model they demonstrate that the effects of restrictions on the ability to go short will have as a result that negative news are incorporated more slowly than positive news. The main contribution of my paper is to explore this hypothesis, and provide a link to the momentum effect. This has been achieved by considering Sweden during the 1980s during which the rare situation of a complete shorting prohibition was enforced. The second section of the thesis foremost addresses the CCAPM model. In the third paper the joint effect of market frictions, different utility specifications, as well as more stringent econometrical analysis, on the CCAPM are considered. Since all these remedies tend to co-exist and should not be considered on a stand alone basis, as has been the case in the previous literature. The paper also shows how several measures of misspecification available in the literature are implemented when market frictions are present. In particular, the paper presents the Hansen and Jagannathan measure with market frictions. The final paper considers L1-norm-based alternatives to the L2-norm-based Hansen and Jagannathan (1997) measure. It is well known that L1-norm methods may show good properties in the presence of non-normal distributions, for instance, with respect to heavy-tailed and/or asymmetric distributions. These methods provide more robust estimators, since they are less easily influenced by outliers or other extreme observations. The basic intuition for this is that L2-norm methods involve squaring errors, which magnifies large deviations, while L1-norm methods are based on absolute deviations. Since financial data are known to frequently display non-normal properties, L1-norm methods have found considerable use in financial economics.