价格信息成本与价格离中现象

该文在Varian(1980)中引入消费者价格信息成本和信息成本的分布,采用Janssen和Moraga(2000)的对称混合策略均衡定义,同时内生化了消费者的信息行为和厂商的定价行为,确定了Varian(1980)中的知情消费者比例,证明了厂商定价正期望利润均衡的存在性.该文证明了,在不完全价格信息条件下,市场普遍存在知情消费者,从而该文加强了Varian(1980)的结论.     

IDENTIFICATION AND ESTIMATION OF AUCTION MODEL WITH TWO‐DIMENSIONAL UNOBSERVED HETEROGENEITY*

This article investigates the empirical importance of allowing for multidimensional sources of unobserved heterogeneity in auction models with private information. It develops the estimation procedure to recover the distribution of private information in the presence of two sources of unobserved heterogeneity. It is shown that this estimation procedure identifies components of the model and produces uniformly consistent estimators of these components. The results of the estimation with highway procurement data indicate that allowing for two‐dimensional unobserved heterogeneity may significantly affect the results of estimation as well as policy‐relevant instruments derived from the estimated distributions of bidders’ costs.     

THE MORPHOLOGY OF PRICE DISPERSION

This article is a study of the shape and structure of the distribution of prices at which an identical good is sold in a given market and time period. We find that the typical price distribution is symmetric and leptokurtic, with a standard deviation between 19% and 36%. Only 10% of the variance of prices is due to variation in the expensiveness of the stores at which a good is sold, whereas the remaining 90% is due, in approximately equal parts, to differences in the average price of a good across equally expensive stores and to differences in the price of a good across transactions at the same store. We show that the distribution of prices that households pay for the same bundle of goods is approximately Normal, with a standard deviation between 9% and 14%. Half of this dispersion is due to differences in the expensiveness of the stores where households shop, whereas the other half is mostly due to differences in households' choices of which goods to purchase at which stores. We find that households with fewer employed members pay lower prices and do so by visiting a larger number of stores instead of by shopping more frequently.     

INCOME DISPERSION AND PRICE DISCRIMINATION

Abstract.  This paper analyses the effects of inter-market and intra-market income heterogeneities on output and social welfare under uniform pricing and differential pricing regimes by considering a finite number of markets. We first derive the linear demand curve in each market under plausible conditions, and then show that more markets (and consumers) are excluded under uniform pricing the higher are the inter-market income differences. We also show that adding markets, even of lower income levels than those of existing markets, helps to decrease prices and thus cause more markets to be served. Implications of intra-market income dispersion are also explored.     

A COMPUTATIONALLY PRACTICAL SIMULATION ESTIMATION ALGORITHM FOR DYNAMIC PANEL DATA MODELS WITH UNOBSERVED ENDOGENOUS STATE VARIABLES*

This article develops a simulation estimation algorithm that is particularly useful for estimating dynamic panel data models with unobserved endogenous state variables. Repeated sampling experiments on dynamic probit models with serially correlated errors indicate the estimator has good small sample properties. We apply the estimator to a model of female labor supply and show that the rarely used Polya model fits the data substantially better than the popular Markov model. The Polya model also produces far less state dependence and many fewer race effects and much stronger effects of education, young children, and husband's income on female labor supply decisions.     

THE MEASUREMENT OF POVERTY WITH GEOGRAPHICAL AND INTERTEMPORAL PRICE DISPERSION: EVIDENCE FROM RWANDA

It is not known to what extent welfare measures result from seasonal and geographical price differences rather than from differences in living standards across households. Using data from Rwanda in 1983, we show that the change in mean living standard indicators caused by local and seasonal price deflation is moderately significant at every quarter. By contrast, the differences in poverty measures caused by this deflation can be considerable, for chronic as well as transient or seasonal poverty indicators. Thus, poverty monitoring and anti-poverty targeting can be badly affected by inaccurate deflation of living standard data. Moreover, when measuring seasonal poverty, the deflation based on regional prices instead of local prices only partially corrects for spatial price dispersion. Using annual local prices instead of quarterly local prices only yields a partial deflation, which distorts the measure of poverty fluctuations across seasons and biases estimates of annual and chronic poverty.     

电子商务市场价格离散度的收敛分析

本文运用信息不对称理论和随机鞅理论分别从基于可得信息集和完全信息集这两个角度深入地探讨了资本市场的信息有效性与资源配置最优性和次优性。在理性预期和交易成本为零的假定下,其基本结论有四:一是资本市场(条件)有效等价于事后帕累托最优,资本市场完全有效等价于事前帕累托最优;二是资本市场事后帕累托最优的充要条件是信息强对称;三是资本市场事前帕累托最优的充要条件是信息强对称和信息强完全;四是不满足信息强对称的资本市场一般只能实现事后帕累托次优,而不同时满足信息强对称和信息强完全的资本市场一般只能实现事前帕累托次优。最后,根据上述观点提出了实现资本市场完全有效或事前帕累托最优的对策建议。     

CONSUMER SEARCH,PRICE DISPERSION,AND INTERNATIONAL RELATIVE PRICE FLUCTUATIONS*

This article develops a model of consumer search consistent with the evidence of substantial price dispersion and time spent shopping within countries to study international deviations from the law of one price (LOP) and relative price fluctuations. Search frictions lead firms to price discriminate across markets based on the opportunity cost of search, which depends on the local wage. With productivity and taste shocks estimated from the data, deviations from the LOP are as volatile and persistent as in the data. Fluctuations in relative wages, real exchange rates, and the terms of trade are also consistent with the data.     

CAN A PERPETUAL INVENTORY CAPITAL STOCK BE USED FOR PRODUCTION FUNCTION PARAMETER ESTIMATION?

Due to lack of data on capital disappearance, we simply do not know the covariance of the capital stock with factor inputs and prices well enough to estimate production function parameters. Since replacement rates are rational economic decisions, the errors in a perpetual inventory capital stock vary systematically with the business cycle and such economic variables as rates of technical progress and interest rates. This introduces systematic errors into calculated parameters of production functions and rates of technical progress.     

INFORMATION AND PRICE DISPERSION: THEORY AND EVIDENCE

Limited information is the key element generating price dispersion in models of homogeneous-goods markets. We show that the global relationship between information and price dispersion is an inverse-U shape. We test this mechanism for the retail gasoline market using a new measure of information based on commuter data from Austria. Commuters sample gasoline prices on their commuting route, providing us with spatial variation in the share of informed consumers. Our empirical estimates are in line with the theoretical predictions. We also quantify how information affects average prices paid and the distribution of surplus in the gasoline market.     

PRICE DISPERSION,INFLATION, AND WELFARE*

We examine the implications of inflation for both price dispersion and welfare in a monetary search economy. In our economy, if the degree of buyers' incomplete information about prices is fixed, both price dispersion and real prices are increasing in inflation. As the inflation rate approaches the Friedman rule, both price dispersion and welfare losses vanish. If households choose the number of prices to observe, then the optimal inflation rate may exceed the Friedman rule as inflation induces search and, up to a point, raises welfare by eroding market power.     

DISCRETE CHOICE MODELS WITH MULTIPLE UNOBSERVED CHOICE CHARACTERISTICS*

Since the pioneering work by Daniel McFadden, utility‐maximization‐based multinomial response models have become important tools of empirical researchers. Various generalizations of these models have been developed to allow for unobserved heterogeneity in taste parameters and choice characteristics. Here we investigate how rich a specification of the unobserved components is needed to rationalize arbitrary choice patterns in settings with many individual decision makers, multiple markets, and large choice sets. We find that if one restricts the utility function to be monotone in the unobserved choice characteristics, then up to two unobserved choice characteristics may be needed to rationalize the choices.