No News Is Good News: Stochastic Parameters versus Media Coverage Indices in Demand Models after Food Scares
提出用随机参数方法替代媒体报道指数，来建模食品恐慌对消费的时变影响，并用四次食品恐慌事件的数据验证，发现该方法能更好捕捉食品安全信息的影响并改进短期预测。
We develop a stochastic parameter approach to model the time‐varying impacts of food scares on consumption, as an alternative to the inclusion of news coverage indices in the demand function. We empirically test the methodology on data from four food scares, the 1982 heptachlor milk contamination in Oahu, Hawaii and the bovine spongiform encephalopathy and two Escherichia coli scares on U.S. meat demand over the period 1993–9. Results show that the inclusion of time‐varying parameters in demand models enables the capturing of the impact of food safety information and provides better short‐term forecasts.