Financial crises, with their manifestations of stock market bubbles and bank failures, create mass phenomena that are expressed through herd behavior. However, there is no compelling methodological approach for researching mass phenomena; this can be done in various ways. The decision-making behavior of individual actors that leads to herd behavior is the focus of Bingyu Zhu's investigation. By classifying the different causes, the formation and impact mechanisms of herd behavior are depicted, and subsequently, measures to counteract this inefficient behavior are proposed. It becomes evident that rational herd behavior can be understood as individuals' response to uncertainty and information asymmetry in the decision-making environment. Through an analysis of the interaction between information and payment externalities, it is explored further.