Observational Learning and Demand for Search Goods
研究了消费者仅观察总购买历史而非完整搜索顺序时，羊群效应如何影响低质量与高质量产品的市场结果，并用在线音乐市场数据检验模型预测。
We develop a model of herds in which consumers observe only the aggregate purchase history, not the complete ordered history of search actions. We show that the purchasing information changes the conditions under which herds can occur for both low- and high-quality products. Inferior products are certain to be ignored; high quality products may be ignored, but complete learning may also occur. We obtain closed form solutions for the probabilities of these events and conduct comparative statics. We test the model's predictions using data from an online music market created by Salganik, Dodds, and Watts (2006).