This paper investigates whether the empirical linkages between stock returns and trading volume differ over the fluctuations of stock markets, i.e., whether the return–volume relation is asymmetric in bull and bear stock markets. Using monthly data for the S&P 500 price index and trading volume from 1973M2 to 2008M10, strong evidence of asymmetry in contemporaneous correlation is found. As for a dynamic (causal) relation, it is found that the stock return is capable of predicting trading volume in both bear and bull markets. However, the evidence for trade volume predicting returns is weaker.

This paper reexamines the explanatory power of Taylor rule fundamentals for real exchange rate determination. We assume the agents know the time-varying parameters in central bank policy rules. The empirical results suggest that a monetary policy rule with regime switching is better able to explain the real Deutschemark/dollar exchange rate from 1976 to 1998 compared with a fixed-regime monetary policy rule. The findings show the importance of accounting for the expectation formation effect in changing policy rules as emphasized by the Lucas critique. Ignoring these effects can undermine the value of the rational expectations models.