Post earnings announcement drift and stock liquidity in the US, the UK and French equity markets

Abstract

This thesis aims to investigate the influence of earnings news on stock liquidity and the relationship between information asymmetry cost component and Post Earnings Announcement Drift in different equity markets. The scope of this research includes 1821 firms from three leading countries in capital trading, the United States, United Kingdom, and France. The first part of empirical work, the univariate panel analysis, shows that price reaction, volume response and liquidity effect are profound during short term event window length and reduce over time when the news ceases, The second part, a multivariate regression analysis which uses Generalised Method of Movement to capture both the problems of a likely presence of endogeneity between the explanatory variables and cross-stock heterogeneity,shows that the impact of earnings announcement on stock liquidity can split in two directions. The immediate effect is the shock after the news, causing stock liquidity to decrease immediately by lifting the illiquidity function upward. After the event, from the new increased position of illiquidity function, stock liquidity improves over time due to the trading volume increases and shifts the slope of illiquidity function downward. The overall effects at a point of time will be the total impact of the two side effects. And as shown in the results, the overall impact on the US and UK markets are that stock liquidity decreases and that on Euronext Paris the stock liquidity increases. Given that in accounting there are two types of systems of which common law system includes the US, UK and others, and code law system includes France and the rest, the above results could suggest the difference between the two systems is that the information asymmetry component dominates the bid-ask spread in common law countries as in the US and UK markets while the cost of trading dominates the bid-ask spreads in code law countries such as France. Finally, it is shown that there are several determinants of the PEAD, of which stock liquidity is one. Earnings news changes the stock liquidity, and therefore stock liquidity plays a role in the market response. When earnings news is released, it initially creates a gap between the informed traders and the uninformed traders, increasing the bid ask spread. Over time, this information gap decreases, however in the meantime more information on the market increases trading volume and reduces trading cost, leading to another part of the bid ask spread decreasing or stock liquidity improving. After decomposing bid ask spread into information asymmetry cost and cost of trading components, the final part of empirical analysis shows that information asymmetry cost component provides a partial explanation for PEAD in the London Stock Exchange and Euronext Paris.