Bandwagon Effect Bias is the tendency to do (or believe) things because many other people do (or believe) the same. It is an example of Cognitive Bias.
Without examining the merits of the particular thing, people tend to “follow the crowd.” Sometimes this cognitive bias is referred to as the Herd Instinct.
Surely this bias is a strong force behind many financial crises.
This human tendency is particularly relevant for investors, leaders of organizations, communication specialists (marketers) and management consultants.