Consumer Demand for Variety: Intertemporal Effects of Consumption, Product Switching and Pricing Policies

Abstract

The concept of diminishing marginal utility is a cornerstone of economic theory. The consumption of a good typically creates satiation that diminishes the marginal utility of consuming more. Temporal satiation induces consumers to increase their stimulation level by seeking variety and therefore substitute towards other goods (substitutability across time) or other differentiated versions (products) of the good (substitutability across products). The literature on variety-seeking has developed along two strands, each focusing on only one type of substitutability. I specify a demand model that attempts to link these two strands of the literature. This issue is economically relevant because both types of substitutability are important for retailers and manufacturers in designing intertemporal price discrimination strategies. The consumer demand model specified allows consumption to have an enduring effect and the marginal utility of the different products to vary over consumption occasions. Consumers are assumed to make rational purchase decisions by taking into account, not only current and future satiation levels, but also prices and product choices. I then use the model to evaluate the demand implications of a major pricing policy change from hi-low pricing to an everyday low pricing strategy. I find evidence that consumption has a lasting effect on utility that induces substitutability across time and that the median consumer has a taste for variety in her product decisions. Consumers are found to be forward-looking with respect to the duration since the last purchase, to price expectations and product choices. Pricing policy simulations suggest that retailers may increase revenue by reducing the variance of prices, but that lowering the everyday level of prices may be unprofitable.