Bank credit and seasonal anomalies in China's stock markets

In this paper, we uncover seasonal anomalies in the Chinese A-share stock markets and examine to what extent they can be explained by bank credit. For the Shanghai and Shenzhen A-share markets over the 1993-2003 period with both monthly and quarterly data, we reject three series of priors: (i) Changes in regulation and investor behavior lead us to expect substantial alterations in the pattern of stock prices, especially in the late 1990s. However, the use of unobserved-components models enables us to uncover no evidence for changes in seasonal patterns over time, once outliers and structural breaks have been properly accounted for. An unchanging positive June effect and a negative December effect have been at work since 1993. (ii) We expect differences between the behavior of prices in Shenzhen and Shanghai, both at the level of the index and in their attractiveness for investors. We find evidence of very similar movements in seasonality between the two markets whatever the frequency. (iii) Seasonality in returns is often considered to be generated by the unofficial channeling of bank credit to the stock market. We find that seasonal effects in returns are robust to the inclusion of bank credit.