does there exist a relation between inflation and relative price change variability the effect of the aggregation level abstract the actual magnitude of relative price change variability is dependent on the level of aggregation this note demonstrates the effect of this dependence when we try to estimate a relation between inflation and relative price change variability and when we perform a decomposition analysis of this variability

further evidence on the variability of inflation and relative price variability abstract using a sample of monthly observations of both a 12 category group and a 203 category group of personal consumption expenditures we furnish evidence that relative price variability is positively related to both the inflation rate and inflation variability the relation is robust to oil price shocks

do switching costs make markets less competitive abstract the conventional wisdom in economic theory holds that switching costs make markets less competitive this article challenges this claim the authors formulate an empirically realistic model of dynamic price competition that allows for differentiated products and imperfect lock in they calibrate this model with data from frequently purchased packaged goods markets these data are ideal in the sense that they have the necessary variation to identify switching costs separately from consumer heterogeneity equally important consumers exhibit inertia in their brand choices a form of psychological switching cost this makes the results applicable to the broad range of products that are distinctly identified i e branded rather than just to products for which there is a product adoption cost or explicit switching fee in the simulations prices are as much as 18 lower with than without switching costs more important equilibrium prices do not increase even in the presence of switching costs that

a folk theorem for one shot bertrand games we show that bounded monopoly profits are essential for the uniqueness of the bertrand paradox zero profit outcome otherwise a folk theorem obtains for one shot homogeneous product bertrand games any positive but finite payoff vector can be achieved in a symmetric mixed strategy nash equilibrium

using price distributions to estimate search costs we show how the equilibrium restrictions implied by standard search models can be used to estimate search cost distributions using price data alone we consider both sequential and nonsequential search strategies and develop estimation methodologies that exploit equilibrium restrictions to recover estimates of search cost heterogeneity that are theoretically consistent with the search models we illustrate the method using online prices for several economics and statistics textbooks

search with learning for differentiated products evidence from e commerce this article provides a method to estimate search costs in a differentiated product environment in which consumers are uncertain about the utility distribution consumers learn about the utility distribution by bayesian updating their dirichlet process prior beliefs the model provides expressions for bounds on the search costs that can rationalize observed search and purchasing behavior using individual specific data on web browsing and purchasing behavior for mp3 players sold online we show how to use these bounds to estimate search costs as well as the parameters of the utility distribution our estimates indicate that search costs are sizable we show that ignoring consumer learning while searching can lead to severely biased search cost and elasticity estimates

maximum likelihood estimation of search costs abstract in a recent paper hong and shum 2006 using price distributions to estimate search costs rand journal of economics 37 257 275 present a structural method to estimate search cost distributions we extend their approach to the case of oligopoly and present a new maximum likelihood method to estimate search costs we apply our method to a data set of online prices for different computer memory chips the estimates suggest that the consumer population can be roughly split into two groups which either have quite high or quite low search costs search frictions confer a significant amount of market power to the firms despite more than 20 firms operating in each of the markets we estimate price cost margins to be around 25 the paper also illustrates how the structural method can be employed to simulate the effects of the introduction of a sales tax

money and the dispersion of relative prices a price dispersion equation is tested with data from the german hyperinflation the equation is derived from a version of lucas s and barro s partial information localized market models in this extension different excess demand elasticities across commodities imply a testable dispersion equation in which the explanatory variable is the magnitude of the unperceived money growth in order to test this hypothesis a price dispersion series is constructed and a measure of the unperceived part of money growth is estimated the model receives support from the empirical analysis although it is evident that unincluded variables have important effects on price dispersion

testing models of consumer search using data on web browsing and purchasing behavior using a large data set on web browsing and purchasing behavior we test to what extent consumers are searching in accordance to various classical search models we nd that the benchmark model of sequential search with a known distributions of prices can be rejected based on the recall patterns we observe in the data moreover we show that even if consumers are initially unaware of the price distribution and have to learn the price distribution observed search behavior for given consumers over time is more consistent with non sequential search than sequential search with learning our

relative price variability inflation and the allocative efficiency of the price system abstract this paper develops a theory of the relationship between aggregate and relative price variability based on the inability of people even in a rational world to identify permanent changes in relative demands whether caused by real or by monetary variability and relative productivities as soon as they occur the theory implies that the variance of the rate of inflation and the variance of relative price change are positively related although expectations are rational and markets always clear production decisions respond sluggishly to changes in relative prices temporary shocks to relative demands cause prolonged changes in the structure of production available information is used so as to maximize the efficiency of the price system however this efficiency decreases when any of the underlying variances increases this decrease is more pronounced when the production lag is longer

the relationship between relative prices and the general price level it is very nearly a truismi amaong neoclassical economists that the public is wont to confuse changes in the general price level with relative price changes correspondingl y one might speak of the independence between the two as one of the central postulates of the neoclassical tradition william stanley jevons was aml ong the first to identify this basic dichotomin economic life as well as to attempt to explain the ordinary citizen s seenming incapacity to understand it

dynamic price competition in auto insurance brokerage we analyze brazilian data on auto insurance and document that a about 20 of policies are sold without brokerage commission b over 40 are sold at the highest fee allowed and c the remaining contracts are associated with a spread out distribution of fees static models cannot rationalize these findings we develop a dynamic model of price competition with search and switching costs that reproduces them we use the equilibrium structure to estimate the model parameters and infer the brokers expected earnings the frequency that insurees switch brokers and the counterfactual effects of a price ceiling policy

price dispersion in mortgage markets using transaction level data on canadian mortgage contracts we document an increase in the average discount negotiated off the posted price and in rate dispersion our aim is to identify the beneficiaries of discounting and to test whether dispersion is caused by price discrimination the standard explanation for dispersion in credit markets is risk based pricing our contracts are guaranteed by government backed insurance so risk cannot be the main factor we find that lenders set prices that reflect consumer bargaining leverage not just costs the presence of dispersion implies a lack of competition but our results show this to be consumer specific

a bertrand model of pricing and entry abstract we analyze an oligopolistic pricing and entry model in which there is a sunk cost of entry and in which firms outputs are homogeneous firms pure strategies consist of a binary entry decision and conditional on entry a uniform or non linear price schedule there does not exist a pure strategy nash equilibrium in this model so we analyze the symmetric mixed strategy equilibrium the main result is that if there exists a positive sunk cost of entry then an increase in the number of potential competitors puts more probability weight on higher prices this result is counter to the usual intuition that underlies current antitrust policy

seasonal fluctuations in industrial production and stock market seasonals february and august peaks in the growth rates of the seasonally unadjusted industrial production index follow the stock market peaks documented by rozeff and kinney 1976 by one month coefficients on one month lead growth rates in industrial production for small firms are positive and significant in time series regressions even in the presence of the market factor moreover whereas returns on large firms stocks unidirectionally gran ger cause i e predict future growth rates in industrial production at least six months in advance returns on small firms stocks reflect one month lead as well as past growth rates in industrial production for these reasons we argue that seasonal real growth provides a partial explanation for the january stock seasonal among small firms

price dispersion in an automobile insurance market from automobile insurance data for alberta over the period 1974 81 we find thatpremiums are highly correlated across driver classes in a given year but that premiums for a given driver class are not correlated over a period of more than 5 years firms relative market shares among drivers over age 25 and married males under 25 are inversely related to their deviations from the mean premiums in these driver classes the variance of real premiums decreases with the numberof firms in the market and increases with the real loss cost per car insured and the number of cars insured from these results we conclude that the price dispersion in automobile insurance in alberta is based on costly consumer search

a note on the variability of inflation and the dispersion of relative price changes abstract the relationship between the variance of inflation and the variability of relative price changes is analyzed empirically a strong positive association is found for 1948 1969 and 1948 1975 application of chow s test indicates structural instability and granger s test suggests a feedback effect between these variables

diagnosing insensitivity to scope in contingent valuation sensitivity to scope is considered a desirable property of contingent valuation studies and often treated as a necessary condition for validity we first provide an overview of scope insensitivity explanations put forth in the environmental valuation literature then we analyze data from a contingent valuation survey eliciting willingness to pay to prevent oil spills of four different magnitudes in arctic norway in the baseline analysis the scope inference is ambiguous there is only statistical difference in willingness to pay to avoid a very large versus small oil spill nok 1869 and nok 1086 respectively however further explorations show that several confounding factors suggested in the literature influence the scope inference the scope sensitivity improves when we control for subjective probabilities of amenity provision exclude respondents based on the debriefing questions take into consideration the sample sizes and impose diminishing marginal utility overall the analysis supports an emerging view in the contingent valuation literature suggesting that statistical scope insensitivity is not a sufficient reason for deeming a study invalid

revisiting dynamic duopoly with consumer switching costs abstract the degree of collusiveness of a market with consumer switching costs is analyzed in an infinite horizon model of duopolistic competition in contrast with previous analyses we assume that firms compete for the demand for a homogeneous good by setting prices simultaneously in each period this problem is formulated as a simple stochastic game and a symmetric stationary markovian perfect equilibrium with distinctive economic features is studied we show that switching costs unambiguously relax price competition in equilibrium but that on the contrary they may make tacit collusion more difficult to sustain journal of economic literature classification numbers c73 d43 l13

existence and persistence of price dispersion an empirical analysis the hebrew university of jerusalem and nber using a unique data set on store level monthly prices of four homogenous products sold in israel i study the existence and characteristics of the dispersion of prices across stores as well as its persistence over time i find that price dispersion prevails even after controlling for observed and unobserved product heterogeneity moreover intra distribution mobility is significant stores move up and down the cross sectional price distribution thus consumers cannot learn about stores that consistently post low prices as a consequence price dispersion does not disappear and persists over time as predicted by varian s 1980 model of sales

the scope trials variation in sensitivity to scope and wtp with directionally bounded utility functions abstract sensitivity to scope refers to the property that willingness to pay for an environmental amenity is an increasing function of the scope of the amenity measurements of the degree of sensitivity to scope are commonly proposed as a test for the reliability of contingent valuation studies we evaluate the traditional scope test using neoclassical utility functions that are directionally bounded we provide a formal definition of sensitivity to scope and show that directionally bounded utility functions can produce arbitrarily small degrees of sensitivity to scope we conclude that a failure to satisfy existing scope tests should not be used as a prima facie basis for rejecting contingent valuation studies this does not imply that small degrees of sensitivity to scope should always be viewed as acceptable rather the results of scope tests should be considered more carefully with attention given to the substitutability of market and non market goods

variability of price changes in oecd member countries abstract this paper considers differences in price changes for 12 countries within the decades 1960 1970 and 1970 1980 it shows that the higher inflation rates of the 1970s were not necessarily accompanied by larger relative price changes but almost invariably by larger year to year fluctuations

what do income tests tell us about the gap between wta and wtp for public goods abstract theory relates the gap between wta willingness to accept compensation and wtp willingness to pay to the income elasticity of wtp it has been suggested that empirical estimates of the income elasticity of wtp can therefore be used to test whether an observed gap between wta and wtp is consistent with rational behavior we examine this issue for the case of non market public goods we identify the theoretically appropriate tests of income sensitivity and examine conditions for valid income sensitivity tests we show that income tests may provide false signals in common settings indicating an inconsistency where none exists

plausible responsiveness to scope in contingent valuation plausible responsiveness to scope is a question of economic significance in addition to statistical significance of the scope test in contingent valuation we briefly review the history of the scope test in order to place the current issue in the context of the bp deepwater horizon oil spill as a result of the review we gain insights into how the issue of scope adequacy arose twenty years after it was first mentioned by the noaa panel on contingent valuation following the exxon valdez oil spill we then provide a review of desvousges mathews and train 2012 who promote the adding up test to identify inadequate responsiveness to scope adequacy the adding up test is a test of the construct validity of the contingent valuation method but is flawed as a measure of economic significance we propose scope elasticity of willingness to pay as a measure of economic significance a simulation suggests a likely range of elasticity estimates given linear and quadratic functional forms for the willingness to pay function in order to illustrate the ease of implementation of scope elasticity within the context of the standard scope test we calculate scope elasticity with willingness to pay estimates from several studies describe two studies that directly estimate scope elasticity and estimate scope elasticity with primary data from two studies all of these empirical estimates of scope elasticity fall within the range of scope elasticity suggested by the simulation scope elasticity provides a practical way forward relative to the adding up test on the issue of economic significance of scope effects

oligopolistic pricing with sequential consumer search n identical stores compete by choosing prices for a homogeneous good with constant marginal costs consumers search sequentially with perfect recall for the lowest price one class of consumers called shoppers have zero search costs while all other consumers have a positive search cost c there is a unique symmetric nash equilibrium price distribution with the property that it changes smoothly from marginal cost pricing when all consumers are shoppers and or c 0 and monopoly pricing when no consumers are shoppers remarkably as the number of stores increases the nash equilibrium becomes more monopolistic copyright 1989 by american economic association

search frictions and market power in negotiated price markets we provide a framework for empirical analysis of negotiated price markets using mortgage market data and a search and negotiation model we characterize the welfare impact of search frictions and

a model of search with price discrimination abstract we introduce observable heterogeneity across buyers into a model of simultaneous search buyers differences are informative about their willingness to search giving rise to price discrimination even if they all have the same willingness to pay we analyze and compare equilibrium outcomes when price discrimination is allowed and when it is not we find that the price comparison across consumers as well as the effects of banning price discrimination critically depend on the elasticity of the search cost distribution interestingly for normally distributed search costs there is an inverted u shape relationship between prices and buyers size similarly a ban on price discrimination hurts small and large buyers to the benefit of the medium size ones

inflation and the distribution of price changes across markets a causal analysis recent advances in time series methodology are applied to the investigation of causal relationships between monthly changes in the consumer price index and changes in its dispersion across different consumption categories this dispersion is associated with the degree to which relative prices are changing past inflation rates seem useful in forecasting changes in relative prices but not vice versa there is also a significant contemporaneous correlation between these series hence it is concluded that fluctuations in the inflation rate help cause fluctuations in relative prices but not vice versa unless the entire effect occurs within a month the analysis also serves to illustrate a new way to implement the granger causality concept

inflation and relative prices a decomposition analysis abstract the variability of relative prices is decomposed into a component due to real effects technical change real income growth and so on and a component due to inflation using quarterly australian data inflation is shown to account for 24 percent of the total relative price variability

inflation variability and relative price change variability in the netherlands 1951 1981 abstract experience with dutch data suggests that the acceptance or rejection of a relationship between inflation variability and relative price change dispersion strongly depends on the statistical specification of the former concept using a new specification for the netherlands a strong positive relationship is found the evidence concerning the direction of causality is inconclusive

variability of inflation and the dispersion of relative prices evidence from the chinese hyperinflation of 1946 1949 abstract this paper uses data from the chinese hyperinflation of 1946 1949 to focus on the relationship between the variability in the general price level and the dispersion in relative prices the issue is important because it bears on the natural rate hypothesis which supports the postulate that these two monetary variables are independent our results reinforce the bulk of previous evidence which suggests a positive correlation between the variation in inflation rate and the dispersion in relative prices during inflationary episodes

inflation and relative price variability in yugoslavia abstract granger causality tests show that inflation granger causes relative price variability but the feedback relationship cannot be excluded

tenure dependence in consumer firm relationships an empirical analysis of consumer departures from automobile insurance firms a typical pattern in markets featuring long term consumer firm relationships is for departure probabilities to decline with tenure a crucial question is whether this actually implies increasing consumer preference for firms if so firms should actively try to convince consumers to remain through the early periods of the relationship and should enter new markets quickly however the pattern can also be explained by selection on unobserved heterogeneity the challenge is to use the data available in these markets generally details on the consumers of one firm to distinguish between these explanations i rely on individual price histories in auto insurance findings include an economically relevant level of both relationship effects and heterogeneity but a much more important role for heterogeneity

equilibrium price dispersion in retail markets for prescription drugs this study seeks to establish the empirical importance of price dispersion due to costly consumer search by examining retail prices for prescription drugs posted prices in two geographically distinct markets are shown to vary considerably across pharmacies within the same market even after one controls for variation due to pharmacy differences pharmacy heterogeneity accounts for at most one third of the observed price dispersion the empirical analysis hinges on the observation that consumers incentives to price shop depend on characteristics of the drug therapy cross sectional patterns in price distributions across drugs are consistent with the predictions of a search model prices for repeatedly purchased prescriptions for which the expected benefits of search are highest exhibit significant reductions in both dispersion and price cost margins

an empirical model of search with vertically differentiated products this paper presents a nonsequential search model that allows for vertical product dierentiation in the unique symmetric equilibrium firms with dierent characteristics draw utilities from a common utility distribution because the firms dier in their characteristics this leads to dierent price distributions the model therefore provides a theoretical rationale for explaining price dispersion as a result of quality dierences and search behavior of consumers together using the equilibrium conditions derived from the model it is shown how to estimate search costs by maximum likelihood using only price data a data set on prices from dutch supermarkets reveals that the amount of search has decreased over the sampling period moreover ignoring vertical product dierentiation results in an overestimation of search costs

willingness to pay and willingness to accept how much can they differ comment i agree with the point made by edoh y amiran and daniel a hagen 2003 that there can be a substantial or even infinite divergence between the wta and wtp for a public good even where there is a nonzero elasticity of substitution between market goods and the public good provided that the indifference curves are asymptotically bounded with respect to market goods in the manner they describe this is an important point they are also correct to point out that the elasticity of substitution is a local concept whereas their asymptotic boundedness condition applies also for discrete changes my 1991 paper used a local analysis because it was following the structure of the analysis in robert d willig 1976 and alan randall and john r stoll 1980 i wanted to show that while randall and stoll appeared to extend willig s local result on wta versus wtp from price changes to changes in the quantity of a public good the relevant elasticity was in fact different and involved the substitution elasticity as well as the income elasticity i view these points by amiran and hagen as not two separate results but essentially the same result their asymptotic boundedness condition generalizes my zero elasticity of substitution condition to discrete changes the asymptotic boundedness condition can be expressed as follows assuming a bivariate utility function u x q and given a reference point x q associated with a reference utility level u u x q there exists some q q such that for all q q there exists no x such that u x q u in other words no amount of x can substitute for the reduction in public good from q to q q in the case of a zero elasticity of substitution q q but as amiran and hagen show in their theorem 1 this is unnecessarily restrictive when dealing with a discrete reduction in q furthermore their theorem 2 can be viewed as a special case of their theorem 1 in which q 0 which makes q an essential commodity it is well known in consumer theory that the wta to avoid the loss of an essential market good is infinite their theorem 2 extends this result to the case of an essential nonmarket good but as their theorem 1 shows essentialness is not necessary for an infinite wta the boundedness condition is the key and this implies a fundamental lack of substitutability between money market goods and the public good

adequate responsiveness to scope in contingent valuation the standard test for scope sensitivity in contingent valuation studies determines whether the response to changes in scope is statistically significant it does not address whether the magnitude of response is appropriate given the specified changes in scope we examine contingent valuation studies that implemented scope tests to determine what they imply about the adequacy of response to scope we find that in the vast majority of studies the magnitude of response cannot be assessed only three studies permit such an assessment samples and hollyer 1990 diamond et al 1993 and chapman et al 2009 the first two papers find that responses to their surveys did not vary adequately with scope the third study passed the standard scope test but we show that the magnitude of response in this study is inadequate by straightforward methods of assessment and cannot be explained by diminishing marginal utility or substitution more research is needed on this issue including wider application of adding up tests on incremental parts as well as the development of other methods that permit an assessment of the magnitude of response or other tests of rationality

inflation and relative price variability effect of temporal aggregation abstract the effect of temporal aggregation on the relation between inflation and variability of relative price changes in the united states is studied by using monthly consumer price index cpi data as well as quarterly observations derived by averaging the monthly series estimates from monthly and quarterly data show major differences for the periods 1973 1986 and 1980 1986

relation between inflation and relative price variability in the united states evidence from data for the 1980s abstract monthly cpi data for 1967 1986 in respect of 10 major categories are utilized the most significant result is a strongly negative association between relative price variability and inflation as well as its expected and unexpected components during the 1980s variations in the estimated coefficients for the three subperiods studied also seem interesting

inflation and relative prices a system wide approach abstract the paper introduces a system wide model for the analysis of the effects of inflation on relative prices this enables the identification of those commodities whose relative prices are distorted by inflation the model provides measures of the natural rate of relative price variability which is associated with zero inflation and the inflation rate which minimizes relative price variability an illustrative application with australian data is provided

a comment on revisiting dynamic duopoly with consumer switching costs a comment on revisiting dynamic duopoly with consumer switching costs eric t anderson nanda kumar and surendra rajiv kellogg school of management northwestern university 2001 sheridan road evanston il 60208 usa school of management university of texas at dallas p o box 830688 richardson tx 75083 0688 usa nus business school national university of singapore biz 1 04 20 1 business link singapore 117592

inflation and relative price variability in the open economy this paper explores the determination of relative price variability in a small open economy operating under a fixed exchange rate a central ingredient of the model presented is the distinction made between traded and non traded goods this distinction leads to a decomposition of total variability into three components the variabilities within each set of goods and between the two sets the analysis also emphasizes the effects of expected versus unexpected inflation on the variability of relative prices the model is tested using annual data for mexico covering the 1951 76 period

intercountry differences in the relationship between relative price variability and average prices this paper provides new evidence on the relationship between relative price variability and inflation the model uses a consistently defined data set for nine european countries it benefits from the inclusion and testing of the effects of macroeconomic variables and the incorporation into the measures of inflation and dispersion adjustments for timeliness appropriate formulas and proximity the general findings of an effect on relative price variability by the macroeconomic environment and negative coefficients on unexpected inflation are supported by their occurrence in models estimated by seemingly unrelated regression and a robust systems estimator

inflation and relative price variability the effect of commodity aggregation using quarterly us data for 1948 89 we study the effect of the level of commodity aggregation on the relation between inflation and relative price variability the effect is assessed for the full period and the subperiods 1948 73 and 1974 89 the relationship is investigated for actual inflation as well as its expected and unexpected components although the parameter estimates show sizeable differences across the two aggregation levels the qualitative picture is the same for both levels in all cases one of the by products of the exercise is the observation that unexpected inflation shows a much stronger positive covariation with relative price variability than the expected component

product differentiation search costs and competition in the mutual fund industry a case study of s p 500 index funds we investigate the role that non portfolio fund differentiation and information search frictions play in creating two salient features of the mutual fund industry the large number of funds and the sizeable dispersion in fund fees in a case study we find that despite the financial homogeneity of s p 500 index funds this sector exhibits the fund proliferation and fee dispersion observed in the broader industry we show how extra portfolio mechanisms explain these features these mechanisms also suggest an explanation for the puzzling late 1990s shift in sector assets to more expensive and often newly entered funds an influx of highinformation cost novice investors