تغییر الگوی شما: یادگیری اجتماعی و منحنی انگل

By relating Engel curves and social learning, we explain the existence of differently shaped Engel curves—an interesting phenomenon in the theory of demand. A formal approach to cultural learning within a population of consumers accounts for some cognitive foundations of these demand patterns. We find that a changing influence of an individual's role models due to her increasing income, which entails new reference groups providing social identity, leads to the diffusion of new consumption behaviors. Thereby, the resulting Engel curves’ shape depends on the underlying learning dynamics. The approach contributes to an explanation of structural change and economic development.

This paper relates social learning and Engel curves. An Engel curve describes how consumers’ purchases of a good or service vary as the consumers’ total resources such as income vary holding prices fixed (Lewbel, 2008). The existence of differently shaped Engel curves is an interesting phenomenon in the theory of demand (e.g., Hausman et al., 1995 and Banks et al., 1997).1 We present a formal approach that accounts for some of their cognitive and behavioral foundations. Thereby, we contribute to an explanation of structural change and economic development that are, to a great extent, the result of systematically changing consumption patterns as per capita income rises.

We presented a simple model of cultural evolution that is capable of explaining differently shaped Engel curves. Following the tradition of Engel curve analysis, our model's demand-originating elements are based on income changes to which we added social learning dynamics. In particular, we argued that a rising income is accompanied by changing reference groups and modified weights of cultural role models providing social identity. Moreover, we imagined different stylized societies characterized by varying social learning dynamics that resulted in different income–consumption curves and corresponding income elasticity of demand functions. Our findings suggest that cultural transmission factors are – under plausible assumptions concerning human learning psychology – an important element in explaining changing patterns in demand. We also showed how some broad patterns of changing demand in the course of economic development observed empirically can be theoretically explained by our model.