The Impact of the GST on Mortgage Yield Spreads of Australian Building Societies

Australia has experienced significant rises in mortgage costs and sharp declines in housing affordability in the last few decades, particularly since it implemented a new tax system of Goods and Services Tax （GST） in July 2000. Prior research has attempted to examine the influence of the GST on general price levels, but little research effort has been directed to investigate the impact of the GST on mortgage costs. Using proprietary data of major building societies in Australia for 36 months, this paper examines the changes of mortgage yield spreads in the pre-and post-GST periods for building societies. Results suggest that the lenders significantly increased their mortgage charges in the post-GST periods, For example, the increase is found to be, on average, 59.0 basis points which are much higher than that of banks.

Margin trading, short selling, and bond yield spread

Using a quasi-natural experiment, this study examines the effects of margin trading and short selling on bond yield spread in China. It finds that both margin trading and short selling can reduce bond yield spread. Additionally, it finds that margin trading lowers firms' debt ratios and increases their credit ratings, which explains the reduced spread. In other words, margin trading can impact investors' decisions by revealing positive information about a firm.Another finding is that short selling lowers the bond yield spread by decreasing earnings management, suggesting that short selling has an impact on investors' decisions through its effect on corporate governance. Our results suggest that margin trading transmits positive information and short selling impacts firms' policies. These results provide support for future regulations of margin trading and short selling.

Downside risk and defaultable bond returns

This paper analyzes the influence of downside risk on defaultable bond returns.By introducing a defaultable bond-trading model,we show that the decline in market risk tolerance and information accuracy leads to trading loss under downside conditions.Our empirical analysis indicates that downside risk can explain a large proportion of the variation in yield spreads and contains almost all valid information on liquidity risk.As the credit level decreases,the explanatory power of downside risk increases significantly.We also investigate the predictive power of downside risk in cross-sectional defaultable bond excess returns using a portfolio-level analysis and Fama-Mac Beth regressions.We find that downside risk is a strong and robust predictor for future bond returns.In addition,due to the higher proportion of abnormal transactions in the Chinese bond market,downside risk proxy semi-variance can better explain yield spreads and predict portfolio excess returns than the proxy value at risk.