The monograph has been prepared in the Latvian language and consists of an introduction and four parts, in total of 263pages. The monograph includes 52 figures and 44 tables, which explain and illustrate the contents of the monograph. During the course of research, 127 various information sources in Latvian, English, German, and Russian language have been used and they are included in the list of bibliography. The first part deals with an analysis of the concept and definitions of consumer behaviour, consumer behaviour models have been considered throughout their historical development, and a critical analysis thereof is performed. The decision-making process has been considered as the grounds for consumer behaviour and the adoption of a decision to make a purchase affected by a family life cycle and by generations. An extensive analysis of consumer behaviour models has been performed with the purpose of discovering their most typical characteristics. In the second part, the changes in consumer behaviour resulting from socially economic factors have been determined, and consequently, the portrait of the Latvian consumer has been developed; components affecting consumer behaviour have been determined and classified; motives of consumer behaviour have been grouped, and the aspects of interaction between the consumer needs, social groups, and classification of goods have been determined. Factors affecting consumer behaviour have been determined and classified in the paper according to the degree of impact on consumer behaviour. The third part presents the results of the study on the components and factors affecting consumer behaviour from a perspective of generations. A correlation between consumer needs and social status has been discovered during the study, as well as the effect of retail personnel on the product selling process and factors affecting consumer behaviour from a perspective of generations. Factors affecting consumer behaviour in retail have been evaluated in accordance with the model of consumer expectations developed by the authors. The fourth part presents a model for decision-making in entrepreneurship has been developed, based on consumer behaviour models considered by the authors’ in the monograph.