This paper demonstrates that investor irrationality can be contagious across markets. Studies addressing the pros and cons of opening derivatives markets have failed to pay sufficient attention to the roles of speculative activities. This paper investigates how trading activities that are unrelated to fundamentals affect the impact of derivatives on stock markets. By using unique data from the ...

tients with Crohn’s disease (7). We saw no difference, so our suggestion of an alkaline phosphatase response to Crohn’s virus infection in man remains unsupported by animal experimentstion. Nevertheless, our speculation may serve to focus further attention on children with transient hyperphosphatasemia and reinforce the importance of the recommendation (3) that such children should receive long...