Book excerpt: Lifestyle and Social Structure: Concepts, Definitions, Analyses is devoted the relationship between lifestyle and social structure. The book begins by constructing a meaningful concept of lifestyle in order to understand and model this relationship. The general formulation of the concept hinges on the descriptive word style, defined as ""any distinctive, and therefore recognizable way in which an act is performed or an artifact made or ought to be performed and made."" After developing the implications of the definition, lifestyle is defined, by analogy, as ""any distinctive, and therefore recognizable mode of living."" The notion of social structure is then introduced, arguing that structural differentiation engenders lifestyle differentiation. The remainder of the work is concerned primarily with the modeling of this relationship using data from the 1972-1973 Survey of Consumer Expenditures, and with the concept of stylistic unity. Key topics discussed include the relationship between the theory of lifestyle differentiation and modern economic utility theory; psychographic notions of lifestyle; and the relationships between lifestyle and other key sociological concepts (stratification, alienation). The concept of lifestyle should be of interest to a broad range of applied and theoretical researchers.