摘要：The economic value of public situation and outlook information has long been a subject of debate. The purpose of this study is to investigate the economic value of USDA reports in hog and cattle markets. The investigation is based on event study analysis, with the "events" consisting of the release of six major USDA situation and outlook reports for hogs and cattle from 1985 through 2003. These include Cattle, Cattle on Feed, Cold Storage, Hogs and Pigs, Livestock, Dairy and Poultry Outlook (LDPO), and World Agricultural Supply and Demand Estimates (WASDE) reports. As a result of the process of modeling volatility of hog and cattle prices, a TARCH-in-mean model was specified that closely followed the distribution of these price movements. The effects of external information were evaluated within this model using dummy variables in the variance equation. The analysis revealed a statistically significant impact of all but Cattle and Cold Storage reports on live/lean hog returns and all but LDPO reports on live cattle returns. Hogs and Pigs reports had the highest impact on live/lean hog returns by increasing average conditional standard deviation by 118.6% following the release of these reports. Cattle and Hogs and Pigs reports had the highest impact on live cattle returns by increasing average conditional standard deviation in both cases 44.8%. These results suggest that the information contained in USDA situation and outlook reports provides economically valuable information to livestock market participants.
