This document discusses several theories of consumer behavior: - Jeremy Bentham's hedonism from 1789 which states that human behavior is guided by seeking pleasure and avoiding pain. - George Katona's theory from 1963 which proposed that consumers are influenced not just by economic factors but also social, political, and psychological factors in their decision making. - Francesco Nicosia's model from 1966 which conceptualized consumer decision making as occurring across four fields: firm and consumer traits, consumer search and evaluation, the act of purchase, and feedback. - John A. Howard and Jagdish N. Seth's model from 1969 which categorized three types of consumer response behavior: extensive problem solving, limited problem solving