Aggregation and pairwise aggregation of demand when the distribution of income is fixed

This paper derives necessary and sufficient conditions for “pairwise aggregation” of the demand functions of a group of consumers (conditions under which the mean demand for each pair of consumers satisfies the Slutsky restrictions) when the distribution of income is fixed. The sufficient conditions imply existence of a “representative” competitive consumer whose demand is the mean demand of the group. The necessary conditions imply that such a representative consumer exists for every fixed income distribution only if the consumers have homothetic preferences or, alternatively, if for each price vector, all the consumers' income expansion paths lie in the same plane.     

An analysis of asymmetric demand response to price changes: The case of local telephone calls

Asymmetric demand responses to price changes are not an observable implication of classical demand theory, which predicts that consumers will react to a small price increase in much the same way as they do to a small price decrease. Yet applied researchers have long speculated that consumers are more sensitive to price increases than they are to price decreases. In addition, recent empirical studies generally support the theory of asymmetric demand responses. We construct a dynamic model based on data gathered from monthly telephone bills for 128 New York Telephone customers over a five-year period. Our results support the conclusion that customers react more quickly and strongly when prices go up than they do when prices go down.We would like to thank Manny Haas and Bernie Reddy for their comments and suggestions.     

Household Electricity Demand, Revisited

Recent efforts to restructure electricity markets have renewed interest in assessing how consumers respond to price changes. This paper develops a model for evaluating the effects of alternative tariff designs on electricity use. The model concurrently addresses several interrelated difficulties posed by nonlinear pricing, heterogeneity in consumer price sensitivity, and consumption aggregation over appliances and time. We estimate the model using extensive data for a representative sample of 1300 California households. The results imply a strikingly skewed distribution of household electricity price elasticities in the population, with a small fraction of households accounting for most aggregate demand response. We then estimate the aggregate and distributional consequences of recent tariff structure changes in California, the consumption effects of which have been the subject of considerable debate.     

A tale of two Italian cities: brand-level milk demand and price competition

We apply the BLP random coefficient logit model demand model to fluid milk sales data from two north-south Italian cities: Turin and Naples. By virtue of their location and socioeconomic differences, these cities provide a natural experiment for contrasting consumer choices and retail market power related to milk physical and marketing characteristics. Results reveal that, regardless of location, consumers negatively value price increases, fat content and ultra-high temperature (UHT) treatment. However, location matters with respect to brand and type of milk purchased. While in Turin (the higher-income region) demand for the leading manufacturers’ brands is the most price inelastic, in Naples consumers have the lowest price elasticities in case of cheaper milk, often small manufacturer or private label brands. Unlike previous studies, we do not find price elasticities for private labels to be consistently lower (or markups to be higher) compared to manufacturer brands, indicating that private labels have reached maturity in these markets. Further, while demand for fresh milk is more price inelastic in Turin, it is more inelastic for UHT milk in Naples. Likewise, markups and Lerner indexes are higher for fresh milk in Turin and for UHT in Naples corresponding to the more inelastic demands under Bertrand price competition.     

Modelling Sri Lankan consumption patterns using error corrected LA-AIDS

Static-demand systems used in empirical studies are based on the assumption that consumers immediately and fully adjust to a new equilibrium when either incomes or prices change. In reality, consumers are unlikely to have adjusted to equilibrium in each time period and the assumption of instantaneous adjustments by consumers is potentially incorrect. The dynamic modelling approach allows for intertemporal rationality of consumer behaviour by explicitly considering the mechanism underlying the short-run adjustment process. This study, while considering the traditional static Almost Ideal Demand System (AIDS), in addition, considers two dynamic versions of the AIDS to model the dynamic behaviour of Sri Lankan consumers in consuming eight broad commodity groups using data during the period 1963–2016. The estimated results indicate that all commodities have price inelastic demand in both the short and long run. The differences between short- and long-run demand elasticities indicate the need to adopt a dynamic approach in estimating demand elasticities, because the income and price elasticities are key inputs for policy analysis in economy-wide modelling.     

How serious is the aggregation problem? An empirical illustration

Heterogeneity in consumer behaviour may create problems with aggregation across consumers. If so, we may not be able to make correct inferences about behaviour based on aggregated data. However, using micro estimates to predict aggregate demand responses to policy changes may also create a bias if not aggregated properly. This may sound like a Catch 22 situation, but it is not, as it is possible to calculate both micro and aggregate demand responses based on microdata. The size of the aggregation bias is an empirical question. In this article, we show how to calculate theoretically consistent aggregate demand responses. We use both micro and macro data for Norwegian household electricity consumption to illustrate the magnitude and direction of different aggregation biases. We find considerable aggregation biases, in particular, when estimating with macro data.     

Revealed smooth nontransitive preferences

In the present paper, we are concerned with the behavioural consequences of consumers having nontransitive preference relations. Data sets consist of finitely many observations of price vectors and consumption bundles. A preference relation rationalizes a data set provided that for every observed consumption bundle, all strictly preferred bundles are more expensive than the observed bundle. Our main result is that data sets can be rationalized by a smooth nontransitive preference relation if and only if prices can normalized such that the law of demand is satisfied. Market data sets consist of finitely many observations of price vectors, lists of individual incomes and aggregate demands. We apply our main result to characterize market data sets consistent with equilibrium behaviour of pure-exchange economies with smooth nontransitive consumers.     

Retailers and consumers in sequential auctions of collectibles

Abstract.  We analyse an independent private-value model, where heterogeneous bidders compete for objects sold in sequential second-price auctions. In this heterogeneous game, bidders may have differently distributed valuations, and some have multi-unit demand with decreasing marginal values (retailers); others have a specific single-unit demand (consumers). By examining equilibrium bidding strategies and price sequences, we show that the presence of consumers leads to more aggressive bidding from the retailers on average and heterogeneous bidders is a plausible explanation of the price decline effect. The study of the expected revenue of the seller confirms the interest of auctioneers in inviting different types of bidders.     

A Bayesian approach to aggregation in demand systems: smoothing with perfect substitution priors

Demand analysis requires aggregation of commodities. Some are imposed at the data collection level, leaving some for the estimation level. When data are collected, the implicit assumption underlying the aggregation is perfect substitutability: one gallon of gasoline is viewed by consumers as equivalent to another gallon; hence, the two are added together. While such aggregation can be carried out further by the data analyst, it is difficult to incorporate perfect substitutability into the estimation of direct demand systems. Perfect substitution in that context implies discontinuous demand functions, which are not nested within standard empirical demand systems. Perfect substitution is much more easily handled in a system of inverse demands, though an empirical method to impose perfect substitutability in an inverse demand system has not previously appeared in the literature. In this article, we develop such a method, which allows perfect substitutability to be imposed as a prior restriction. We use Leamer’s information contract curve as a tool to flexibly impose the substitution restriction and to investigate consistency between the data and prior. We illustrate the method with an application to inverse demands for fish in Korea.     

Dual price and quantity aggregation

In his seminal 1959 paper (in Econometrica), Gorman developed conditions for price aggregation in the context of income-constrained utility maximization. Price aggregation is defined as the existence of group income allocation functions with price indices and income as arguments. This paper develops and proves propositions about quantity aggregation that are dual to the Gorman results. These dual structures contain interesting asymmetries. The quantity aggregation concepts should be useful in the study of organizational structures characterized by decentralized shadow price (demand price) determination.     

Exact aggregation and Generalized Slutsky Conditions

This article indicates a natural connection between Generalized Slutsky Conditions and demand structures of the exact aggregation form. It is shown that Generalized Slutsky Conditions are assured when the number of consumers is greater than or equal to the number of goods, if and only if demands are of a generalized exact aggregation form. This result provides some understanding of the properties of aggregate demand and allowable differences between consumers, as well as naturally generalizing W. M. Gorman's (Econometrica21 (1953), 63–80) famous conditions for the integrability of aggregate demand.     

Price transmission and local market power: empirical evidence from the Austrian gasoline market

We analyse the impact of local market power on price margins and different dimensions of price adjustment dynamics (speed and asymmetry of price transmission) using data for a large number of individual gasoline stations in Austria. Specific attention is paid to threshold effects in price adjustment. Our results clearly suggest that the speed of price transmission between the Brent crude oil index and retail diesel prices is higher in a more competitive environment. While evidence on the relationship between local market power and asymmetries in the speed of price adjustment is mixed, our findings regarding asymmetries in price thresholds are clear: in regions where competition from neighbouring rivals is weak and/or consumers’ price elasticity of demand is low (stations located on the highway), positive thresholds significantly exceed negative ones, which corresponds to the ‘rockets and feathers phenomenon’. As expected, we observe that prices are lower in more competitive local markets.     

Nonlinear pricing with self-control preferences

A basic assumption of economics is that consumers choose what they want. However, many consumers find it difficult to stop overeating, overspending, smoking, procrastinating, etc, even though they want to. In reality, consumers have temptation and it is psychologically costly to exercise self-control. To clarify the implications of the existence of temptation and self-control costs, this paper studies a firm's optimal selling strategy exploiting the behavioral features of consumers. We characterize optimal nonlinear pricing schemes for a monopoly when self-control is costly for consumers. Since consumers have a preference for commitment, the firm faces a trade-off between offering a small menu that makes the consumers’ self-control easier and offering a large menu that achieves better price discrimination. We show that the optimal menu resembles the one in the standard nonlinear pricing problem with a price ceiling, where the upper bound on prices is determined endogenously by a participation constraint. The ceiling motivates the firm to offer a relatively flat and compact price schedule, serving more consumers with low demand. The characterization also shows that the firm may earn less if consumers have temptation.     

Welfare from a benefit viewpoint

Summary Individual welfare is most naturally measured in terms of individual utility but this has the well-known disadvantage that utility levels of different consumers cannot be meaningfully compared. This difficulty is traditionally avoided by using various willingness-to-pay measures, such as compensating and equivalent variation. These measures are based on price changes. This paper develops alternative welfare measures using willingness-to-trade concepts as originally proposed by Dupuit (1844). These measures are based directly on commodity bundle changes. These welfare measures can be represented as integrals under certain inverse demand functions.An important property of the proposed welfare measures studied here is that they can be meaningfully aggregated to form overall welfare measures. These measures in turn directly quantify a compensation criterion. It is shown that competitive prices provide a first-order approximation to the welfare measures. Furthermore a second-order approximation can be found by forming a suitable aggregation of the individual second-order effects.Finally, it is shown that the representations for consumer welfare as integrals under inverse demand curves can be extended to the aggregate measures as well. This then provides a complete complement to traditional measures based on price changes.This research was supported by Grant SES-9022881 from the National Science Foundation. The author wishes to thank Andrew Yates for valuable suggestions on this paper.     

Demand for Piped and Non-piped Water Supply Services: Evidence from Southwest Sri Lanka

In many countries water supply is a service that is seriously underpriced, especially for residential consumers. This has led to a call for setting cost recovery policies to ensure that the tariffs charged for water supply cover the full cost of service provision. Identification of factors driving piped and non-piped water demand is a necessary prerequisite for predicting how consumers will react to such price increases. Using cross-sectional data of 1,800 households from Southwest Sri Lanka, we estimate water demand functions for piped and non-piped households using appropriate econometric techniques. The (marginal) price elasticity is estimated at  − 0.15 for households exclusively relying on piped water, and at  − 0.37 for households using piped water but supplementing their supply with other water sources. The time cost elasticity for households relying on non-piped water only is estimated at  − 0.06 on average, but varying across sources. For both piped and non-piped households, we find evidence of substitutability between water from different sources. We discuss the implications of these results in terms of pricing policy.     

品牌经济学的理论基础——引入品牌的需求曲线及其经济学分析

需求定律是经济学分析的理论基础之一,品牌经济学的理论基础为引入品牌的需求曲线或考虑选择成本的需求定律。把品牌引入经济学中后,品牌信用度的提高使需求曲线右移并变得更为陡峭,同时品牌信用度的提高改变了需求曲线的位置,使得均衡价格提高,均衡数量增加,增加了消费者剩余和生产者剩余,提高了社会福利水平。文章为“品牌战”替代“价格战”提供了理论依据,即通过品牌建设提高品牌信用度,使得在价格提高的条件下需求量增加,而这只有在需求曲线改变位置时方能做到。     

水价确定的经济学分析——基于南水北调工程

科学的水价形成机制是南水北调工程成功的关键因素之一。本文根据水资源的商品属性,分析了水资源的供给模型和需求模型,进而采用供求均衡模型来分析合理的水价形成机制。并根据水市场的垄断性质,运用价格歧视理论分析了对不同的用户采用不同的水价的科学性。     

Empirical regularities in South African consumption patterns

This article investigates a number of empirical regularities in the South African consumption patterns. The data support the following empirical regularities: (1) variability in consumption systematically exceeds the variability in prices; (2) law of demand; (3) income flexibility is about ?0.5; (4) Engel's law; and (5) the demand hypotheses, demand homogeneity and Slutsky symmetry are acceptable. In contrast to the findings for a number of other countries, another important empirical regularity that consumer's utility function is additive is rejected for the South African consumers. Based on the implied demand elasticity estimates from the preferred model, it is found that food, housing and medical care are necessities, and clothing, furniture, transport and recreation are luxuries and demand for all the commodities are price inelastic.