This chapter fi rst introduces several theories on consumption such as the life cycle hypothesis, precautionary saving model, behavioral life cycle hypothesis, hyperbolic consumption model consumption benefi ts and costs, and decision making styles. Then the research literature related to consumer expenditures over the life cycle and in several major expenditure categories such as housing, transportation, food, and health care is described. After introducing the topic of consumer confi dence, the research literature on desirable and undesirable consumption behaviors is reviewed. Desired consumption behaviors include smart shopping, sustainable consumption, ethical consumption, and socially responsible consumption. Undesirable consumption behaviors refer to conspicuous consumption, unethical consumption, compulsive buying, impulsive buying, and overspending.