do mergers really reduce costs evidence from hospitals in this paper we compare potential and realized cost savings from hospital mergers our approach isolates changes in realized cost savings due to different output mixes from systematic changes due to time and also provides a measure of the potential cost savings due to scale economies our findings suggest that economies of scale are present for merging hospitals and they realize these cost savings immediately following a merger however we also show that over time cost savings from the merger decrease and the proportion of hospitals experiencing positive cost savings declines

durable goods theory for real world markets the early 1970s witnessed three major advances in durable goods theory swan 1970 1971 and sieper and swan 1973 on optimal durability coase 1972 on time inconsistency and akerlof 1970 on adverse selection this paper surveys durable goods theory starting with these three contributions where much of the focus is on recent literature and on models that explain real world phenomena in addition to the ideas found in the contributions of swan coase and akerlof topics covered include why producers sometimes practice planned obsolescence the role of adverse selection in new car leasing and reasons for aftermarket monopolization

advertising learning and consumer choice in experience good markets an empirical examination this article empirically analyzes different effects of advertising in a nondurable experience good market a dynamic learning model of consumer behavior is presented in which i allow both informative effects of advertising and prestige or image effects of advertising this learning model is estimated using consumer level panel data tracking grocery purchases and advertising exposures over time empirical results suggest that in this market advertising s primary effect was that of informing consumers the estimates are used to quantify the value of this information to consumers and evaluate the welfare implications of an alternative advertising regulatory regime

the timing and magnitude of retail store markdowns evidence from weekends and holidays we examine daily prices of eight goods at seventeen retail stores collected in ann arbor michigan over a four month period from november 1 to february 28 we focus on weekly and seasonal price patterns and on the frequency of price markdowns or sales there were frequent markdowns in the intensive shopping period prior to christmas and a tendency for such sales to occur on weekends we interpret these findings as evidence that a significant number of markdowns are timed to occur when shopping intensity is exogenously high we complement the imperfect information based motives for sales in the literature by contributing an additional element based on the role of bulk shopping and increasing returns in the shopping technology

outsourcing retail pricing to a category captain the role of information firewalls it has been argued that retailers lack both the resources and capabilities to maximize category performance retailers may seek category management cm advice from a manufacturer referred to as a category captain cc a cc s recommendations affect all brands in the category not just her own despite an increase in the number of cc collaborations retailers are still concerned about manufacturer opportunism and militant behavior by manufacturers not selected as ccs whereas government agencies are worried about anticompetitive behavior that could harm consumers the federal trade commission recommends strictly enforced information firewalls within a cc s organization as a best practice guideline in this study we develop an empirical model and use policy simulations to quantify the impact of cc arrangements with information firewalls on retailers manufacturers and consumers we show how these effects could be influenced by the deactivation of vertical and horizontal information firewalls within the cc s organization

market structure and media diversity i introduction information on news and current affairs can raise political awareness and promote a range of ideas under the assumption that unregulated media markets supply too little variety many societies have charged regulators with ensuring there are sufficient opportunities for different new and independent viewpoints diversity and that media respond to the interests of their local communities localism 1 the federal communications commission fcc has traditionally limited the amount of common and cross ownership of newspapers radio and television tv stations recently the fcc relaxed ownership rules and refocused their attention on market forces for example consumer preferences and new media such as satellite the internet and smartphone in order to achieve their diversity and localism goals given the increase in choices through new media supporters of greater ownership concentration argue that traditional media should be free to consolidate and use the efficiencies to provide more diverse and local news programming opponents question whether such efficiencies are achievable and argue that large consolidated media corporations are not flexible enough to serve the interests of local and minority communities in this paper we estimate consumer preferences for their local news and current affairs news service described by the offerings from newspapers radio tv the internet and smartphone news service characteristics are diversity of opinion in the reporting of information coverage of multiculturalism issues amount of information on community news and events and amount of space or time devoted to advertising we use our demand estimates to calculate the impact on consumer welfare from a change in media market structure that reduces the number of independent tv stations in the market by one specifically we employ the willingness to pay wtp construct to measure the expected consumer welfare effects between the news service supplied to the consumer before the change in market structure and the service supplied after the change we focus on broadcast tv stations because they are the main news for most households and because the fcc has direct oversight of their ownership we estimate our demand model with data obtained from a nationwide survey of households during march 2011 results show that the representative consumer is willing to pay from 18 to 26 per month for an increase in diversity of opinion and slightly more for community news from a low to a medium level but only an additional 6 to 7 to move to a high level of diversity of opinion or community news the representative consumer also values an improvement in information that reflects the interests of women and minorities from low to medium 7 the representative consumer is willing to pay about 5 to avoid a change from a low to a medium level of advertising but the much higher amount of 20 to avoid a change from a medium to a high level using fcc 2011 data on media market structure we present evidence that indicates the amount of diversity localism and advertising in the news services supplied to consumers is lower in markets with one fewer independent tv station as a result the average small market i e five or fewer tv stations consumer loses 83 per month whereas the average large market i e 20 or more tv stations consumer loses 37 per month these losses are equivalent to 45 million annually for all small market households in the united states and 13 million for large market households if the change in market structure occurs in all markets aggregate losses nationwide would be about 681 million other studies have measured the relationship between information on news and current affairs and market structure flowever these studies measure supply from just one of the media sources that comprise the consumer s news service for example milyo 2007 gentzkow 2007 and gentzkow and shapiro 2010 for newspapers and siegelman and waldfogel 2001 and crawford 2007 for radio and tv

exchange rates and cash flows in differentiated product industries a simulation approach how do exchange rate changes impact firms cash flows we extend a simulation method developed in industrial organization to answer this question we use prices quantities and product characteristics for differentiated products coupled with a discrete choice framework and an assumption of price competition to estimate marginal costs for all producers using a monte carlo approach we generate counterfactual prices and profits for different levels of exchange rates we illustrate the method using the market for bottled water our results stress that even in a relatively simple market such as this one different brands face very different exchange rate risks consider a firm that produces a good in france using mainly local inputs and sells it abroad in locations that have a floating exchange rate vis a vis the euro profits and in turn the value of the firm are potentially exposed to exchange rate changes if the euro appreciates profits when measured in euros are likely to decrease how large is the decrease in profits similarly what is the impact of such an exchange rate change on the profits of an import competing firm these are the questions that a large literature on exchange rate exposure attempts to answer

diffusion and the international context of democratization democracy does not evolve sui generis the spatial clustering in democ racy and transitions suggests that international factors play a prominent role in forg ing democracies as well as influencing their durability we argue that democracy often comes about as a result of changes in the relative power of important actors and groups as well as their evaluations of particular institutions both of which are often influenced by forces outside the country in question the scope and extent of con nections with other democratic countries in a region can strengthen support for dem ocratic reform and help sustain institutions in transitional democracies results from a transition model demonstrate that international factors can exert a strong influence on the prospects for transitions to democracy and the spatial clustering in democ racy and transitions cannot adequately be explained by the hypothesized domestic social requisites of individual countries

what difference does dynamics make the case of digital cameras abstract when the well known blp model is applied to products with rapid technological changes and declining prices it tends to yield implausible results a sequence of increasingly sophisticated dynamic demand models most recently gowrisankaran and rysman 2009 hereafter gr have been developed to overcome these problems we apply both models to new data on the us digital camera market in addition we demonstrate that the gr model can be specified as a blp model plus an additional set of terms this suggests that a dynamic model can be estimated as a blp model plus a non parametric function which is less computationally demanding as a first step to implementing this semi parametric approach we estimate a blp model augmented with age as a proxy for the non parametric component we find that demand for digital cameras is more elastic when demand dynamics is accounted for in both the dynamic model and the blp model with the age proxy this suggests that the market is more competitive though the results are consistent with firms engaging in intertemporal price discrimination merger simulations predict the lowest price and quantity changes using the gr model

additional information for comments on alternative models of demand for automobiles by charlotte wojcik abstract in a recent paper in this journal econ lett 68 2000 113 wojcik argues that the nested logit is likely to be superior to demand specifications we and others have used in recent empirical work we review the relevant models and their uses consider her application and find that her conclusions are incorrect

product differentiation cost reducing mergers and consumer welfare cost synergies are an explicitly recognized justification for a two firm merger and empirical techniques are now widely used to assess the impact of cost reducing mergers on prices and welfare in the post merger market we show that if the merger occurs in a vertically product differentiated market then the merger will lead to a reduction in product offerings that limits the usefulness of pre merger empirical estimates indeed we further show that in such markets two firm mergers will typically lead to higher prices regardless of the merger s cost savings jel classifica tion l10 l41 differentiation des produits fusions pour reduire les couts et bien etre du consommateur les synergies de couts sont une justification explicitement reconnue pour la fusion de deux firmes et il existe des techniques empiriques vastement utilisees pour mesurer l impact des fusions visant areduire les couts sur les prix et le niveau de bien etre dans le marcheapres la fusion on montre que si la fusion se produit dans un marchede produit differencieintegreverticalement alors la fusion reduit l even tail de produits ce qui limite l utilitedes estimations empiriques faites avant la fusion de plus on montre que dans de tels marches les fusions de deux firmes finissent par engendrer des prix plus eleves quelles que soient les reductions de couts auxquelles on en arrive

competition and mergers in the retail market for toys i study competition between big box retailers k mart and wal mart and toy retailers kb toys and toys r us with the aim of estimating wal mart s effect on the profits of toy retailers using rece

spatial differentiation and vertical mergers in retail markets for gasoline this paper studies an empirical model of spatial competition applied to gasoline markets the main feature is to specify commuting paths as the locations of consumers in a hotelling style model as a result spatial differentiation depends in an intuitive way on the structure of the road network and the direction of traffic flows the model is estimated using panel data on the quebec city gasoline market and used to evaluate the consequences of a recent vertical merger difference in difference and counterfactual simulation methods are compared and the results to a large extent validate the assumptions of the demand model jel g34 l13 l42 l81 q41 r41

on modeling the advertising operations interface under asymmetric competition abstract using a market share attraction structure of advertising competition and following a supermodular game approach this article demonstrates for an asymmetric oligopoly the directional impact of changes in model parameters on the marketing controlled variables of all rivals advertising budgets and the operations controlled variables of all rivals ordered quantities importantly the various changes are examined analytically empirically and numerically in both non dominated and dominated asymmetric oligopolies in this regard the results indicate that firms in a dominated oligopoly one firm of market share larger than or equal to 50 behave differently compared to firms in a non dominated oligopoly each firm of market share less than 50 in response to changes in model parameters furthermore changes in model parameters are investigated in terms of their relative influential impact on a variety of equilibrium measures in this regard the findings indicate that for the analyzed model the marketing parameters exert much more influence on the equilibrium measures than the operations parameters additionally a change in the mode of competition from non cooperation oligopoly to cooperation joint ownership dictates that strong asymmetric firms of favorable marketing and operations parameters continue advertising but at lower levels and weak asymmetric firms of less favorable parameters cease advertising altogether

measuring the effects of search costs on equilibrium prices and profits abstract this paper assesses the effects of search costs on equilibrium prices and profits using an estimated model of demand and costs in a laundry detergent market i find that some firms profits initially rise and then fall with search costs overall the magnitude and direction of the search costs effects on prices and profits are heterogeneous this is because search costs create conflicting incentives for a firm to reduce prices to attract the attention of searching consumers yet also raise prices to harvest profit from consumers who are unaware of competing products these effects can vary with the relationship between the firms actual prices and the consumers pre search beliefs about prices

more evidence on the performance of merger simulations government antitrust agencies must predict the price effects of proposed mergers and chal lenge those predicted to reduce consumer wel fare merger simulation a model of oligopoly combined with demand estimates is routinely used to simulate the effects of potential merg ers gregory j werden and luke m froeb 2006 provide a survey merger simulation addresses the key question regulators must answer would a potential merger reduce consumer welfare however it requires strong assumptions on the nature of competition both before and after the merger occurs the shape of demand and mar ginal cost functions as well as the statistical assumptions necessary to consistently estimate demand given these strong assumptions and the substantial resources devoted to antitrust review it is important to evaluate the accuracy of simulation methodology this paper adds to a small literature that evaluates merger simu lation by comparing predicted price effects to retrospective estimates of the price effects of a

applied welfare economics with discrete choice models economists have been paying increasing attention to the study of situations in which consumers face a discrete rather than a continuous set of choices such models are potentially very important in evaluating the impact of government programs upon consumer welfare but very little has been said in general regarding the tools of applied welfare economics indiscrete choice situations this paper shows how the conventional methods of applied welfare economics can be modified to handle such cases it focuses on the computation of the excess burden of taxation and the evaluation of quality change the results are applied to stochastic utility models including the popular cases of probit and logit analysis throughout the emphasis is on providing rigorous guidelines for carrying out applied work this abstract was borrowed from another version of this item

mergers with differentiated products the case of the ready to eat cereal industry traditional merger analysis is difficult to implement when evaluating mergers in industries with differentiated products i discuss an alternative which consists of demand estimation and the use of a model of postmerger conduct to simulate the competitive effects of a merger i estimate a brand level demand system for ready to eat cereal using supermarket scanner data and use the estimates to 1 recover marginal costs 2 simulate postmerger price equilibria and 3 compute welfare effects under a variety of assumptions the methodology is applied to five mergers two of which occurred and for which i compare predicted to actual outcomes

copyright and artists a view from cultural economics most of the standard economic literature on copyright ignores a number of aspects that have considerable significance for cultural production and for artists the primary creators of copyright works the supply of which copyright is supposed to stimulate specifically there is little mention in that literature of moral rights no distinction is made between copyright for authors and neighbouring rights for performers the distributional effects of copyright are barely referred to and the question of how much artists earn from copyright is ignored in this article i survey work that relates copyright and cultural economics showing that cultural economics offers another view to the standard economics of copyright moreover the case for government intervention in the arts and heritage made by cultural economists has resonance for the economic rationale of copyright

characteristics of demand for pharmaceutical products an examination of four cephalosporins we model demand for four cephalosporins and compute own and cross price elasticities between branded and generic versions of the four drugs we model demand as a multistage budgeting problem and we argue that such a model is appropriate to the multistage nature of the purchase of pharmaceutical products in particular the prescribing and dispensing stages we find quite high elasticities between generic substitutes and also significant elasticities between some therapeutic substitutes

estimating market power in a two sided market the case of newspapers the newspaper industry is a two sided market the readers market and the advertising market are closely linked by inter market network externalities we estimate market power in the italian newspaper industry by building a structural model which encompasses a demand estimation

cost pass through in differentiated product markets the case of u s processed cheese in this paper we estimate a mixed logit model for demand in the u s processed cheese market the estimates are used to determine pass through rates of cost changes under different behavioral regimes we find that under collusion the pass through rates for all brands fall between 21 and 31 while under nash bertrand price competition the range of pass through rates is between 73 and 103 the mixed logit model provides a more flexible framework for studying pass through rates than the logit model since the curvature of the demand functions depends upon the empirical distribution of consumer types

a larger slice or a larger pie an empirical investigation of bargaining power in the distribution channel this research aims to provide insights into the determinants of channel profitability and the relative power in the channel by considering consumer demand and the interactions between manufacturers and retailers in an equilibrium model we use the nash bargaining solution to determine wholesale prices and thus how margins are split in the channel equilibrium margins are a function of demand primitives and of retailer and manufacturer bargaining power bargaining power is itself a function of exogenous retail and manufacturer characteristics the parties bargaining positions are determined endogenously from the estimated substitution patterns on the demand side the more they have to lose in a negotiation relative to an outside option the weaker the bargaining position we use the proposed bargaining model to investigate the role of the three main factors that have been blamed for the power shift from manufacturers to retailers in recent years firm size increases store brand introductions and service level differentiation in our empirical analysis of the german market for coffee we find that bargaining power varies among the different manufacturer retailer pairs this result suggests that bargaining power is not an inherent characteristic of a firm but rather depends on the negotiation partner we are able to confirm empirically previous theoretical findings that there can be cases where the slice of the pie that goes to one of the channel members may decrease but the overall pie increases and compensates for the smaller share of profits

should further mergers be allowed product differentiation and merger in the external audit market the external audit market in us is a market with noticeable features a highly concentrated market various choice patterns of auditors and the sequential mergers of big auditors over time there has been growing concern about the impact of mergers and the increasing market concentration using a flexible multinomial probit model and micro level data on over 3000 public companies this article investigates production differentiation and merger in the external audit service market between the big four accounting firms based on the estimation results of the demand estimates a model of post merger conduct is then used to simulate the competitive effects of a merger the results suggest that merger effects on prices in this market are not significant with no larger than 3

demand for differentiated durable products the case of the u s computer printer market i introduction this paper aims to provide a theoretical and empirical description of consumer behavior in a dynamic market for differentiated durable goods the computer hardware industry serves as an example of the type of market we consider markets for computer systems and components as well as for many other high technology products exhibit some striking similarities that are of particular concern for an empirical economist as follows products are differentiated in multiple dimensions in addition to price products are durable yielding consumption services over multiple periods product quality rapidly improves over time empirical work on estimating differentiated product demand systems has been dominated by static discrete choice models with random utility see berry levinsohn and pakes 1995 goldberg 1995 and nevo 2001 among others however markets for durable goods exhibit several features at odds with their assumption of myopic consumer behavior first traditional static discrete choice models implicitly assume that consumers participate in the market every period choosing one of the available products or an outside option thus the fraction of consumers who do not buy any product in a given period could only be explained by the high value they assign to the outside alternative for durable goods however purchases are made infrequently and result in a consumer s exiting the market for a significant period of time hence the model needs to account for consumers outflow from the market arising from their purchase decisions second a static framework may give a misleading picture of the aggregate sales time pattern in a dynamic industry in many markets for durable products it is not uncommon to see rapidly improving product quality and falling prices given any reasonable set of consumer preferences over the product characteristics space static discrete choice models for such an industry will tend to predict an upward trend in aggregate sales this fails to account for a variety of patterns commonly seen in the data third the evolution of product quality leads to the possibility of intertemporal demand substitution by forgoing a current purchase the consumer retains the option to buy a potentially better product in the future hence the decision of when to buy may be just as important for consumers as the decision of what to buy this trade off cannot be accounted for in the static framework the purpose of this paper is to remedy these shortcomings of static discrete choice models in durable goods markets with particular attention paid to technological change and the dynamics of new products adoption the paper presents a dynamic model of consumer demand for differentiated durable products that explicitly accounts for consumers expectations of future product quality and consumers outflow from the market that arises endogenously from their purchase decisions in this model the consumer faces a sequence of static discrete choice problems over a non stationary choice set we show that for a subclass of random utility models which include the multinomial logit and the mcfadden 1978 generalized extreme value gev model there exists a scalar valued sufficient statistic that determines the value of the option to postpone the purchase this allows us to model industry evolution over a vastly reduced state space and to formalize the consumer s decision of when to buy as an optimal stopping problem a solution to that problem defines the hazard rate of product adoptions while the nested discrete choice model determines the alternative specific purchase probabilities integrating individual decisions over the population distribution generates rich dynamics of aggregate and product level sales the paper proceeds to present monte carlo evidence that ignoring the time dimension of consumer choice will induce a downward bias in the estimates of consumer preferences over quality sometimes reversing the sign of the coefficients

the welfare effects of restricted hospital choice in the us medical care market summary managed care health insurers in the usa restrict their enrollees choice of hospitals to within specific networks this paper considers the implications of these restrictions a three step econometric model is used to predict consumer preferences over health plans conditional on the hospitals they offer the results indicate that consumers place a positive and significant weight on their expected utility from the hospital network when choosing plans a welfare analysis assuming fixed prices implies that restricting consumers choice of hospitals leads to a loss to society of approximately 1 billion per year across the 43 us markets considered this figure may be outweighed by the price reductions generated by the restriction copyright 2006 john wiley sons ltd

airline code share alliances and their competitive effects abstract code share alliances have become a prominent feature in the competitive landscape of the airline industry however policy makers are extremely hesitant to approve proposed code share alliances when the potential partners route networks have significant overlap the main concern is that an alliance may facilitate price collusion on partners overlapping routes this article shows how policy makers can use a structural econometric framework to quantify the competitive effects of proposed code share alliances where potential alliance partners compete on overlapping routes in the prealliance industry as an example i apply the econometric model to the delta continental northwest alliance this proposed alliance was initially greeted with skepticism by the u s department of transportation owing to the potential partners unprecedented level of route network overlap for the markets considered in my analyses it appears as though the ultimate approval of the alliance by policy makers was justified

where are we now on cultural economics a survey of progress in cultural economics since its virtual birth in 1966 with the publication of baumol and bowen performing arts the economic dilemma distinguishing between theoretical progress and empirical progress following in the footsteps of towse s recent anthology of classic papers in cultural economics i address nine topics that between them cover the subject namely 1 taste and taste formation 2 demand and supply studies 3 the media industries 4 the art market 5 the economic history of the arts 6 the labour market for artists 7 baumol s cost disease 8 non profit arts organisations and 9 public subsidies to the arts i conclude that there has been some theoretical and empirical progress in the treatment of almost all these topics

the gains from merger or collusion in product differentiated industries a merger in an industry with differentiated products increases the market power of the merging firms to the extent that their products are close substitutes and that other firms produce only more distant substitutes such a merger makes the residual demand curve of each partner steeper by shifting each in the direction of the industry demand curve 2 the extent of this increase in market power depends upon the own elasticity of demand for each merging firm s product as well as the cross elasticity of demand for each with all other firms products as a result evaluating the effect of a merger between two firms with n 2 other competitors would seem to require the estimation of at least n2 parameters all of the price elasticities of demand a formidable task that extremely difficult estimation task is unnecessary however the necessary information is contained in the slopes of the two single firm residual demand curves before the merger and the extent to which the merged firm will face a steeper demand curve for example suppose a merger between two u s brewing firms say pabst and anheuser busch were proposed it is not particularly important to determine whether it is competition from miller or competition from stroh or from heileman or which puts the most effective brake on anheuser busch s pricing only the total effect of these other firms and the particular effect of competition from pabst are of interest this paper proposes econometric procedures for estimating the demand system that merger partners will face based only on pre merger data the key to the procedures is that the effects of all other firms in the industry are summed together formally we start with a model of an n firm product differentiated industry manipulation of the model removes the prices and quantities of all but two firms this reduces the dimensionality of the problem to manageable size rather than an n firm demand system we estimate a two firm residual demand system in this way the technique extends our econometric method for

estimation of a model of entry in the airline industry this paper considers the effect of an airline s scale of operation at an airport on the profitability of routes flown out of that airport the empirical methodology uses the entry decisions of airlines as indicators of underlying profitability the results extend the empirical literature on airport presence by providing a new set of estimates of the determinants of city pair profitability these estimates imply that city pair profits increase in airport presence and decrease rapidly in the number of entering firms the literature on empirical models of oligopoly entry is also extended via a focus on the role of differences between firms

quantifying the coordinated effects of partial horizontal acquisitions abstract recent years have witnessed an increased interest by competition agencies in assessing the competitive effects of partial acquisitions we propose an empirical structural methodology which can deal with settings involving all types of owners and ownership rights to quantify the coordinated effects of partial horizontal acquisitions on differentiated products industries by evaluating the impact of such acquisitions on the minimum discount factors for which coordination can be sustained we also provide an empirical application of the methodology to several acquisitions in the wet shaving industry that give rise to cross and common ownership structures the results are as follows i the incentives to coordinate of the firms that the acquiring party is pre acquisition able to influence are non decreasing with any acquisition ii the incentives to coordinate of the acquired firm are non decreasing with acquisitions involving full or partial both financial and corporate control rights but non increasing with acquisitions involving full or partial solely financial rights and iii the incentives to coordinate of the remaining firms in the industry are non increasing with any acquisition this implies that the coordinated effects of partial horizontal acquisitions are in general ambiguous which illustrates the importance of an empirical structural methodology

supermarket choice and supermarket competition in market equilibrium multi store firms are common in the retailing industry theory suggests that cross elasticities between stores of the same firm enhance market power to evaluate the importance of this effect in the u k supermarket industry we estimate a model of consumer choice and expenditure using three data sources profit margins for each chain a survey of consumer choices and a data set of store characteristics to permit plausible substitution patterns the utility model interacts consumer and store characteristics we measure market power by calculating the effect of merger and demerger on nash equilibrium prices demerger reduces the prices of the largest firms by between 2 and 3 8 depending on local concentration mergers between the largest firms lead to price increases up to 7 4

estimating multiple discrete choice models an application to computerization returns buyers in many markets face multiple discrete choices they can purchase multiple units as well as multiple brands at the same time this paper presents a multiple discrete choice model for the analysis of differentiated products demand users maximize profits by choosing the number of units of each brand they purchase i estimate the model using micro level data on the demand for personal computers i use the estimated demand structure to assess the welfare gains from computerization and technological innovation in peripherals the estimated return on investment in personal computers is 92 moreover a 10 increase in the performance to price ratio of microprocessors leads to a 2 2 gain in the estimated user surplus the personal computer pc market is of interest to industrial organization economists because of its size the continual technological change and above all because of the farreaching implications of pcs on the economy as a whole several distinct features make pc demand difficult to model pcs are a differentiated durable good in constant technological evolution moreover buyers make multiple discrete choices firms according to our data spread their purchases of pcs over different brands at the same time they buy pcs in blocks several units of each brand that they have chosen the aim of the paper is to present a model that captures these features and to use this model to estimate the welfare gains from computerization classical discrete choice models allow one choice among mutually exclusive alternatives in contrast the proposed framework allows users to demand multiple units and multiple brands the model can be applied to other cases of multiple discrete choices e g the composition of airline fleets car holdings per household the fields of the faculty in economics departments household cereals consumption or any other good consumed in more than one variety during a relevant time period although pervasive multiple discrete choice problems have received little attention because of their complexity a central issue regarding the pc market is the current controversy in the economics literature about the computerization puzzle this puzzle stems from the empirical finding that computerization has had no effect on firm productivity griliches and siegel 1991 and morrison and berndt 1990 contrary to those results hendel 1994 and lichtenberg 1995 using more disaggregate data than most previous studies report excess returns to computerization this indicates that data aggregation may have created the computerization puzzle in this paper i present a model consistent with the basic

reassessing the three waves of democratization since the publication of samuel huntington s 1991 study of democratization scholars have come to take for granted the notion that the spread of democracy has come in waves although huntington s work has clearly proved to be an influential study this article suggests that his analysis is far from compelling there are two problems embodied in the work the first is largely conceptual huntington s analysis fails to provide a clear and meaningful distinction between democratic and authoritarian regimes because it focuses primarily on what dahl had defined in 1971 as the dimension of competition and pays insufficient attention to the equally important dimension of inclusion the second problem is more empirical huntington has estimated the incidence of transitions to democracy in terms of the percentages of world states involved since the denominator in this equation that is the number of states in the world is far from constant this measure can be misleading this article proposes solutions to both of these problems and this new approach leads to conclusions that are quite different from huntington s the new findings are important not only because they suggest a somewhat altered sequencing and a more accurate count of democratization waves but also because they cast real doubt on the appropriateness of the wave metaphor as the reverse waves are not really apparent from these data these results therefore also indicate that future studies should be cautious in comparing explaining and forecasting different waves of democratization

choice inconsistencies among the elderly evidence from plan choice in the medicare part d program comment consumers enrollment decisions in medicare part d can be explained by abaluck and gruber s 2011 model of utility maximization with psychological biases or by a neoclassical version of their model that precludes such biases we evaluate these competing hypotheses by applying nonparametric tests of utility maximization and model validation tests to administrative data we find that 79 percent of enrollment decisions from 2006 to 2010 satisfied basic axioms of consumer theory under the assumption of full information the validation tests provide evidence against widespread psychological biases in particular we find that precluding psychological biases improves the structural model s out of sample predictions for consumer behavior

one is almost enough for monopoly it has been argued that two factors product durability and potential entry may force a monopolist to price at marginal cost this article shows that when these two forces coexist the tendency toward competition may be negated first we prove that durable goods oligopolists without commitment powers may attain joint profits arbitrarily close to those of a monopolist with perfect commitment power second we demonstrate that the presence of a potential entrant may enable a durable goods monopolist to act as if he had commitment power thus potential as well as actual entry may restore monopoly power

breaking out of the coup trap political competition and military coups in latin america this article systematically assesses whether open political competition ends the coup trap we use an original data set of coup reports electoral competition and socioeconomic data spanning the 20th century in 18 latin american countries our models which are robust to multiple comparison tests generate support for a central claim while recent experience with military coups increases the risk of incumbents being overthrown the establishment of open political competition ends cycles of political instability the risk of being overthrown consequently declines with time for presidents in noncompetitive systems but remains stable and on average substantially lower in competitive polities coups do not vary with levels of development or of inequality economic growth rates or the legislative powers of the presidency

choice set heterogeneity and the role of advertising an analysis with micro and macro data abstract the authors show how to use microlevel survey data from a tracking study on brand awareness in conjunction with data on sales and advertising expenditures to improve the specification estimation and interpretation of aggregate discrete choice models of demand in a departure from the commonly made full information assumption they incorporate limited information in the form of choice sets to reflect that consumers may not be aware of all available brands at purchase time they find that both the estimated brand constants and the price coefficient are biased downward when consumer heterogeneity in choice sets is ignored these biased estimates can lead firms to make costly price setting mistakes in addition the tracking data enable the authors to identify separately two processes by which advertising influences market shares they find that advertising has a direct effect on brand awareness inclusion in choice set in addition to its effect on consumer preferences increase in utility this

multiple job holding the artist s labour supply approach this article analyses a labour supply model in which individuals maximize a utility function that depends on leisure time consumption and time devoted to an activity that is termed artistic this activity may generate income that depends nonlinearly on hours dedicated to it the individual can also work in the labour market an activity that does not increase utility by itself in exchange for an hourly wage and obtain income not related to hours conditions are obtained that sort individuals into two groups part time and full time artists deriving their labour supply functions in both activities the predictions of the model are tested empirically using a sample of musicians from a uruguayan performing rights society increases in outside wages drive part time artists out of the labour market but no significant increase in arts hours is detected higher nonlabour income also reduces nonarts work time of part time artists but does not have a significant impact in their arts hours conversely arts

the welfare impact of hmo mergers abstract this paper estimates the welfare consequences of hmo mergers using data from california s small group market the analysis estimates the parameters from a differentiated products demand system the parameters are then used to simulate the effects of several hmo mergers by solving for the nash equilibrium in prices under different ownership structures even small mergers in moderately concentrated markets can result in significant consumer surplus reductions however these welfare losses can be offset by large efficiency gains the welfare consequences of hmo mergers turn less upon demand side considerations than on the health plan s ability to realize efficiencies

demand estimation and merger simulations for drugs logits v aids abstract we use adhd drugs sales data from 2000 2003 and compare estimates of elasticities and merger simulations from three different demand models models include logit random coefficients logit and conditional aids demand model with multistage budgeting the magnitude of cross price elasticities is larger in the third model in comparison to the first two and some of the cross price elasticities are estimated to be negative hypothetical merger simulations show larger price effects for the multistage aids model in comparison to the discrete choice models

a structural approach to market definition with an application to the hospital industry a structural approach to market definition market definition is essential to merger analysis because no standard approach to market definition exists opposing parties in antitrust cases often disagree about the extent of the market these differences have been particularly relevant in the hospital industry where the courts have denied seven of eight merger challenges since 1994 due largely to disagreements over geographic market definition we compare geographic markets produced using common ad hoc methodologies to a method that directly applies the ssnip test to hospitals in california using a structural model our results suggest that previously employed methods overstate hospital demand elasticities by a factor of 2 4 to 3 4 and define larger markets than would be implied by the merger guidelines s hypothetical monopolist test the use of these methods in differentiated product industries may lead to mistaken geographic market delineation and was likely a contributing factor to the permissive legal environment for hospital mergers

quantifying the effects from horizontal mergers comments on the underlying assumptions in our paper published in this issue we measured the effects of the proposed volvo scania merger we first estimated an oligopoly model with product differentiation and then used the parameter estimates to compute the post merger equilibrium and the implied price and welfare changes under various alternative scenarios in section 4 4 of our paper we discussed what we view as the most important sources of concern regarding our empirical analysis in part based on the comments from the experts hired by volvo during the case the hausman leonard hl paper elaborates in more detail on the specific points raised by the experts during the case in this note we respond to these points

partial identification and mergers this paper discusses policy choice under ambiguity in the context of merger simulation we do so by incorporating the uncertainty about post merger conduct into a simple merger simulation model we isolate the problem of uncertainty regarding post merger conduct by working with a simple conduct parameters model in the spirit of bresnahan 1982 and lau 1982 we then apply manski s 2011 analysis and discuss policy choice under the maxmin minimax regret and expected utility criteria