Comparing the impact of news: A tale of three health care sectors

This paper examines the impact of news on the volatility of equity returns in three sectors of the health care industry - health care service providers, producers of drugs and supplies, and third-party payors. The news impact is found to be asymmetric in that bad news (i.e., a negative shock) has a significantly greater effect on volatility than good news. Intra-industry differences in health care equity market performance are documented and are consistent with the fundamental attributes of these sectors including the degree of price and cost pressures facing firms, the physical capital requirements of firms, the search behavior of health care customers, and the presence of alternative market opportunities.