design and analysis of simulated consumer choice or allocation experiments an approach based on aggregate data the authors integrate concepts in conjoint analysis and discrete choice theory in econometrics to develop a new approach to the design and analysis of controlled consumer choice or resource allocat

utility covariances and context effects in conjoint mnp models experimental conjoint choice analysis is among the most frequently used methods for measuring and analyzing consumer preferences the data from such experiments have been typically analyzed with the multinomial logit mnl model however there are several problems associated with the standard mnl model because it is based on the assumption that the error terms of the underlying random utilities are independent across alternatives choice sets and subjects the multinomial probit model mnp is well known to alleviate this assumption of independence of the error terms accounting for covariances in utilities in modeling choice experiments with the mnp is important because variation of the coefficients in the choice model may occur due to context effects previous research has shown that subjects utilities for alternatives depend on the choice context that is the particular set of alternatives evaluated simonson and tversky s tradeoff contrast principle describes the effect of the choice context on attribute importance and patterns of choice they distinguish local contrast effects which are caused by the alternatives in the offered set only and background contrast effects which are due to the influence of alternatives previously considered in choice experiments these effects are hypothesized to cause correlations in the utilities of alternatives within and across choice sets respectively the purpose of this study is to develop an mnp model for conjoint choice experiments this model is important for a more detailed study of choice patterns in those experiments in developing the mnp model for conjoint choice experiments several hurdles need to be taken related to the identification of the model and to the prediction of holdout profiles to overcome those problems we propose a random coefficients rc model that assumes a multivariate normal distribution of the regression coefficients with a rank one factor structure on the covariance matrix of these regression coefficients the parameters in this covariance matrix can be used to identify which attributes and levels of attributes are potentional sources of dependencies between the alternatives and choice sets in a conjoint choice experiment we present several versions of this model moreover for each of these models we allow utilities to be either correlated or independent across choice sets the independent probit ip model is used as a benchmark given the dimensionality of the integrations involved in computing the choice probabilities the models are estimated with simulated likelihood where simulations are used to approximate the integrals involved in the choice probabilities we apply and compare the models in two conjoint choice experiments in both applications the random coefficients mnp model that allows choices in different choice sets to be correlated rc displays superior fit and predictive validity compared with all other models we hypothesize that the difference in fit occurs because the rc model accommodates correlations among choice sets that are caused by background contrast effects whereas the model that treats choice sets as independent irc accounts for local contrast effects only the irc model shows superior model fit compared with the ip model but its predictions are worse than those of the ip model we find differences in the importance of local and background contrast effects for choice sets containing different numbers of alternatives the background contrast effect may be stronger for smaller choice sets whereas the local contrast effect may be stronger for bigger choice sets we illustrate the differences in simulated market shares that are obtained from the rc irc and ip models in three hypothetical situations product modification product line extension and the introduction of a me too brand in all of those situations substantially different market shares are predicted by the three models which illustrates the extent to which erroneous predictions may be obtained from the misspecified irc and ip models

hospital choices hospital prices and financial incentives to physicians we estimate an insurer speci c preference function which rationalizes hospital referrals for privately insured births in california the function is additively separable in a hospital price paid by the insurer the distance traveled and plan and severity speci c hospital xed eects capturing hospital quality we use an inequality estimator that allows for errors in price and detailed hospital severity interactions and obtain markedly dierent results than those from a logit the estimates indicate that insurers with more capitated physicians are more responsive to price capitated plans send patients further to utilize similar quality lower priced hospitals but the cost quality trade odoes not vary with capitation rates the patient protection and aordable care act of 2010 includes provisions to establish ac countable care organizations acos in the medicare program these are groups of health care providers that oer services to a large number of patients and are eligible to share in any cost savings they achieve for the medicare program 1 private sector acos are forming in parallel to this initiative often with very similar structures and payment arrangements the proportion of savings acos keep is linked to their performance on quality standards the goal of the initiative is to reduce health care costs in both medicare and private insurance and to improve coordination of care the tying of cost savings to quality standards is designed to mitigate the concern that an increase in incentives to control costs might lead to a decrease in the quality of care the health policy literature has noted that similar cost control incentives are currently utilized by some health maintenance organizations hmos in california and elsewhere 2 in this paper we investigate the impact of these incentives on the cost and quality of care provided to patients focusing in particular on the choice of hospital for privately insured patients giving birth we use

physician induced demand for surgery following up the earlier findings by fuchs on surgeon induced demand this paper makes numerous data and econometric improvements in conducting a test of neoclassical and inducement theories a simultaneous equation model is used to estimate physician demand and equilibrium fees for surgery from a sample of 350 psus over the 1969 76 period the results provide definite support for the notion of competitive market failure particularly in large metropolitan areas other things equal fees and utilization are higher in surgeon rich areas although our estimated shift elasticities were only about one third those found by fuchs a statistically significant albeit small price elasticity of demand for surgery was also obtained in contrast to fuchs increasing monopoly and disequilibrium models are also tested without altering the basic findings where surgeons were in short supply their availability significantly affected surgery rates although a small supply effect was found in plentiful areas as well

hospital transaction prices and managed care discounting for selected medical technologies it is generally assumed that managed care has been successful at capturing discounts from medical providers but the implications have been a matter of debate critics argue that managed care organizations attain savings by reducing intensity of services while others have argued that savings are real and are a consequence of discounts per unit of care rather than reduced intensity because medical services tend to be bundled together into episodes of care separating out prices and quantities can be difficult given available data past studies focused on an average price for the aggregate hospital calculated from total revenue divided by the number of inpatient days or cases e g glenn a melnick et al 1992 emmett b keeler and melnick 1999 david dranove and richard ludwick 1999 caution that these methods provide approximations of actual prices and are subject to measurement error due to unobservable differences in service mix examining treatment episode for acute myocardial infarctions heart attacks david cutler et al 2000 infer that discounts attained by managedcare plans are only partly due to reductions in intensity here we employ data that enable us to observe transaction prices i e actual payments borne by the payer and received by the hospital for major procedures on an unbundled basis our analysis differs from previous studies in several important dimensions among these is the focus on pricing differences between various insurers and employers rather than differences within a single large insurer as a consequence we derive an empirical specification based on the bargaining framework due to john m brooks et al 1997 rather than their insurerbased model moreover to identify pure unit discounts we focus on the narrowly defined procedure like cutler et al we focus on coronary heart disease a leading cause of death we examine a major procedure used to treat this disease one that is costly and relatively common in bypass surgery more fully coronary arterial bypass graft or cabg healthy segments of artery are surgically inserted around the diseased arteries in 2002 about 344 000 cabg s were performed in the united states with expenditures exceeding 21 billion other economists have focused on these procedures to examine market phenomena such as the hospital s entry decision michael chernew et al 2002 or information diffusion dranove et al 2003 yet the pricing decision was not treated fully

estimation of consumer demand with stock out based substitution an application to vending machine products the occurrence of temporary stock outs at retail is common in frequently purchased product categories available empirical evidence suggests that when faced with stock outs consumers are often willing to buy substitute items an important implication of this consumer behavior is that observed sales of an item no longer provide a good measure of its core demand rate sales of items that stock out are right censored while sales of other items are inflated because of substitutions knowledge of the true demand rates and substitution rates is important for the retailer for a variety of category management decisions such as the ideal assortment to carry how much to stock of each item and how often to replenish the stock the estimated substitution rates can also be used to infer patterns of competition between items in the category in this paper we propose methods to estimate demand rates and substitution rates in such contexts we develop a model of customer arrivals and choice between goods that explicitly allows for possible product substitution and lost sales when a customer faces a stock out the model is developed in the context of retail vending an industry that accounts for a sizable part of the retail sales of many consumer products we consider the information set available from two kinds of inventory tracking systems in the best case scenario of a perpetual inventory system in which times of stock out occurrence and cumulative sales of all goods up to these times are observed we derive maximum likelihood estimates mles of the demand parameters and show that they are especially simple and intuitive however state of the art inventory systems in retail vend ing provide only periodic data i e data in which times of stock out occurrence are unobserved or missing for these data we show how the expectation maximization em algorithm can be employed to obtain the mles of the demand parameters by treating the stock out times as missing data we show an application of the model to daily sales and stocking data pooled across multiple beverage vending machines in a midwestern u s city the vending machines in the application carry identical assortments of six brands since the number of parameters to be estimated is too large given the available data we discuss possible restrictions of the consumer choice model to accomplish the estimation our results indicate that demand rates estimated naively by using observed sales rates are biased even for items that have very few occurrences of stock outs we also find significant differences among the substitution rates of the six brands the methods proposed in our paper can be modified to apply to many nonvending retail settings in which consumer choices are observed not their preferences and choices are constrained because of unavailability of items in the choice set one such context is in store grocery retailing where similar issues of information availability arise in this context an important issue that would need to be dealt with is changes in the retail environment caused by retail promotions

hospital systems and bargaining power evidence from out of market acquisitions competition analyses generally restrict their attention to how mergers alter concentration in the relevant consumer market studying hospital competition by focusing on the local patient market may be misleading however as multi market hospital systems often play an important role in the price negotiations of their members with managed care organizations we focus on out of market hospital mergers to investigate the cross market effects of system membership on member hospital reimbursement rates based on acquisitions occurring across the united states during 2000 2008 we find that hospitals exhibit significant increases of around 14 in their net reimbursement rates after becoming affiliated with an out of market system compared to independent stand alone hospitals we find no evidence that the price effect results from changes in patient case mix the cost of providing care generally or hospital quality the findings reveal that systems can impact the market power of hospitals in ways that have not been considered in recent antitrust analysis

insurer hospital bargaining negotiated discounts in post deregulation connecticut this paper uses unique data from the state of connecticut to examine discounting patterns in the state s hospital industry for the years following deregulation 1995 1998 the data provide a rare opportunity to study payer level differences in negotiated discounts for hospital services in addition to presenting descriptive evidence on how discounts vary across payers payer types and hospital types this study uses matched revenue data to analyze the economic determinants of discount magnitudes payer size appears to affect bargaining power but the economic significance of the effect is small the data exhibit patterns consistent with a bargaining explanation in which discount magnitudes depend critically on payers abilities to channel patients to hospitals with which favorable discounts have been negotiated

inferred and stated attribute non attendance in food choice experiments we review the current literature on attribute non attendance in stated choice and use data from beef and chicken choice experiments using both inference and the respondents own statements inference is based on panel data analysis by mixed logit models of choice with both discrete and continuous mixtures of coefficients and is conditional on the observed pattern of choice information from respondent statements on non attendance is directly embedded in the specification of the indirect utility function results show no clear winner between the inferential approaches but the inference based on constrained latent class panel models better matches the observed data

applying conjoint analysis in economic evaluations an application to menorrhagia the increased demand for health care coupled with limited resources means that decisions have to be made concerning the allocation of scarce health care resources this paper considers how conjoint analysis ca can be used to aid this decision making process it is shown how the technique can be used to estimate marginal rates of substitution between attributes willingness to pay wtp if cost is included as an attribute and overall utility scores for different ways of providing a service the technique is applied to consider women s preferences for two surgical procedures in the treatment of menorrhagia hysterectomy and conservative surgery the results suggest conservative surgery is preferred to hysterectomy as indicated by higher utility scores for the former and a marginal wtp of 7593 to have conservative surgery rather than hysterectomy the internal validity of ca was also shown it is concluded that ca is a potentially useful instrument for policy makers however numerous methodological iss

incentive aligned conjoint analysis abstract because most conjoint studies are conducted in hypothetical situations with no consumption consequences for the participants the extent to which the studies are able to uncover true consumer preference structures is questionable experimental economics literature with its emphasis on incentive alignment and hypothetical bias suggests that more realistic incentive aligned studies result in stronger out of sample predictive performance of actual purchase behaviors and provide better estimates of consumer preference structures than do hypothetical studies to test this hypothesis the authors design an experiment with conventional hypothetical conditions and parallel incentive aligned counterparts using chinese dinner specials as the context the authors conduct a field experiment in a chinese restaurant during dinnertime the results provide strong evidence in favor of incentive aligned choice conjoint analysis in that incentive aligned choice conjoint outperforms hypothetical choice conjo

is fairness blind the effect of framing on preferences for effort sharing rules this paper uses a choice experiment to study citizens preferences for effort sharing rules for reducing carbon dioxide emissions for a given global cost and level of emission reduction we study the willingness to pay for various rules that imply different distributions of the cost between eu the us china and africa the focus of this paper is on the use of two different treatments one where the respondents were informed about the country or country group names and one where the names were replaced with anonymous labels a d this allows us to test whether people s preferences for effort sharing rules depend on the framing of the problem we find that the ranking of the rules and the strength of the preferences are not significantly different between the two treatments and hence we find no evidence of ingroup bias in preferences for effort sharing rules c 2011 elsevier b v all rights reserved less

style of practice and assortative mating a recursive probit analysis of cesarean section scheduling in italy we study practice variation in scheduling of caesarean section cs delivery across public and private hospitals in italy adopting a novel perspective we look at the role played by patients preferences for the treatment the recursive probit model is revisited as a useful tool to assess the presence of assortative mating of patients and provider driven by style of practice according to our evidence the propensity to schedule a cs is codetermined with patient self sorting into hospital types we measure a significantly higher inclination to practice cs scheduling in private hospitals and conclude that assortative mating is of minor relevance in our case even if we cannot exclude it to be present

constructive consumer choice processes consumer decision making has been a focal interest in consumer research and consideration of current marketplace trends e g technological change an information explosion indicates that this topic will continue to be critically important we argue that consumer choice is inherently constructive due to limited processing capacity consumers often do not have well defined existing preferences but construct them using a variety of strategies contingent on task demands after describing constructive choice consumer decision tasks and decision strategies we provide an integrative framework for understanding constructive choice review evidence for constructive consumer choice in light of that framework and identify knowledge gaps that suggest opportunities for additional research

market share constraints and the loss function in choice based conjoint analysis choice based conjoint analysis is a popular marketing research technique to learn about consumers preferences and to make market share forecasts under various scenarios for product offerings managers expect these forecasts to be realistic in terms of being able to replicate market shares at some prespecified or base case scenario frequently there is a discrepancy between the recovered and base case market share this paper presents a bayesian decision theoretic approach to incorporating base case market shares into conjoint analysis via the loss function because defining the base case scenario typically involves a variety of management decisions we treat the market shares as constraints on what are acceptable answers as opposed to informative prior information our approach seeks to minimize the adjustment of parameters by using additive factors from a normal distribution centered at 0 with a variance as small as possible but such that the market share constraints are satisfied we specify an appropriate loss function and all estimates are formally derived via minimizing the posterior expected loss we detail algorithms that provide posterior distributions of constrained and unconstrained parameters and quantities of interest the methods are demonstrated using discrete choice models with simulated data and data from a commercial market research study these studies indicate that the method recovers base case market shares without systematically distorting the preference structure from the conjoint experiment

on the instability of long run money demand and the welfare cost of inflation in the united states we evaluate the policy implications of measuring the welfare cost of inflation accounting for instabilities in the long run money demand for the u s over the period 1900 2013 we extend the analysis and reassess the results reported in lucas 2000 and ireland 2009 also considering the recent theoretical contributions of lucas and nicolini 2015 and berentsen et al 2015 breaks in the long run money demand give rise to regime dependent welfare cost estimates we find that the welfare cost is about 0 1 of annual income over 1976 2013 as compared to 0 8 over 1945 1975 overall these values are substantially lower than those reported in the literature

addressing preference heterogeneity multiple scales and attribute attendance with a correlated finite mixing model of tap water choice unobserved heterogeneity of error scale in choice models is a recent extension of the better investigated issue of heterogeneity of taste intensity it is achieved by fitting choice panel data with specifications that simultaneously handle inter personal variation in scale and taste the aim is to separate differences in preference intensities across respondents from differences in the degree of consistency in choice behaviour or preference discrimination while accounting for correlation between the two another recent substantive issue in choice data analysis is attribute non attendance we develop a finite mixing model to address simultaneously the three issues above we empirically prove the concept on stated preference data related to tap water attributes in a study for industry regulation

non elective c sections in public hospitals capacity constraints and doctor incentives abstractusing administrative records of births from the perinatal surveillance system of the peruvian social security system essalud we test whether high admissions of pregnant women affected non elective caesarean section c section rates in the essalud public hospitals during 2005 2006 we present a basic theoretical model that considers physician preferences for leisure and hospital capacity constraints and test the model predictions we find that physician demand for leisure increases the probability of c sections in small and medium size hospitals while hospital capacity constraints set a limit on them we discuss the policy implications as well as the policies implemented to avoid unnecessary c sections

managed care s price bargaining with hospitals research has shown that managed care mc slowed the rate of growth in health care spending in the 1990s primarily via lower unit prices paid however the mechanism of mc s price bargaining has not been well studied this article uses a unique panel dataset with actual hospital prices in massachusetts between 1994 and 2000 to examine the sources of mc s bargaining power i find two significant determinants of price discounts first plans with large memberships are able to extract volume discounts across hospitals second health plans that are more successful at channeling patients can extract greater discounts patient channeling can add to the volume discount that plans negotiate

demand for money in thailand after a brief review of recent literature new estimates on a long run of annual observations of the thai demand for all the standard measures of money are presented the results demonstrate that the demand for real money balances is a stable function of a scale variable and a coherent measure of opportunity cost with all the properties predicted by economic theory

social security national policies with international implications social security policies within individual countries are determined independently by national governments but the resulting outcome is inefficient compared with what would result from the international co ordination of policies this is because national social security policies produce international externalities via their effects on world interest rates an illustrative example suggests that the gains from co ordination are potentially significant virtually all countries operate social security or redistributive policies each chooses policies independently and to my knowledge no one either in a policymaking context or in the large literature on international policy co ordination has suggested that such decisions would benefit from international coordination 1 however a simple argument suggests that independent national social security policies are inefficient more specifically in the long run national governments make policy decisions which are too egalitarian this holds provided that social security lowers national saving in this case each national government faces a trade off between income redistribution and national saving and can be assumed to locate at the nationally optimal point on this trade off taking as given the world interest rate the latter is clearly not independent of the combined effect of all countries policies however if all countries expand social security the resulting fall in world saving will raise the world interest rate with adverse consequences for each national economy each country rationally ignores its own small contribution to the global outcome if this international externality were internalised by co ordination countries would relocate on the trade off between income redistribution and national saving demonstrating the existence of an externality says nothing about its quantitative significance i address this with an example which focuses on pay as you go payg retirement pensions in an economy with a mixture of forward looking and myopic individuals the pensions prevent destitution among retired myopes and thus effectively redistribute life time welfare but they also lower saving because of payg financing for all parameter values considered international co ordination of pensions policy decisions generates welfare gains which are larger for many parameter values substantially larger than recent estimates of the welfare gains from either the entire elimination of all cyclical fluctuations or the reduction of inflation and nominal interest rates from suboptimally high to optimal levels hence the issues addressed in the paper are quantitatively significant when judged against other frequently advocated i am grateful to two anonymous referees for helpful comments on earlier versions they are not responsible for the present version

an econometric model of health care utilization and health insurance in switzerland abstract this paper presents a preliminary econometric analysis on how different alternative plans affect the utilization of health care services in switzerland the data come from the 1992 1993 swiss health survey shs we briefly describe some institutional aspects of the swiss health system which prevailed at the time of the shs with particular emphasis on health insurance plans and payment system of providers we estimate a simultaneous two equation model containing latent variables in order to compare the probability of having at least one inpatient stay given that the insured has used some medical treatment for those who have purchased only a basic insurance plan and those who have purchased a supplemental insurance

shoe leather costs reconsidered lucas has recently suggested that the shoe leather costs of inflation may amount to as much as 1 of gnp in the united states when moving to the friedman optimum we assess his thesis using empirical evidence for the united kingdom over the period 1870 1994 we find support for lucas proposition that interest rates should be specified in logs as a description of money demand dynamics but not as a steady state characterisation although lucas estimates can be corroborated a semilog interest rate specification implies smaller though still tangible welfare gain estimates for example 0 22 of gnp in perpetuity when moving from 6 to 2 nominal interest rates

hospital insurer bargaining an empirical investigation of appendectomy pricing employers increased sensitivity to health care costs has forced insurers to seek ways to lower costs through effective bargaining with providers what factors determine the prices negotiated between hospitals and insurers the hospital insurer interaction is captured in the context of a bargaining model in which the gains from bargaining are explicitly defined appendectomy was chosen because it is a well defined procedure with little clinical variation our results show that certain hospital institutional arrangements e g hospital affiliations hmo penetration and greater hospital concentration improve hospitals bargaining position furthermore hospitals bargaining effectiveness has diminished over time and varies across states

the hospital physician interaction in u s hospitals evolving payment schemes and their incentives abstract unlike the case in several european countries where physicians are salaried employees of the hospital in the u s physicians are independent agents who are granted admitting privileges by their affiliated hospitals hospitals and physicians bill separately for their components of inpatient care and patients or insurers compensate them separately this has raised questions about the degree of efficiency and cooperation between the agents in the first part of this paper we review previous models that examined this interaction under cost based and prospective reimbursement in the second part we consider an experimental mechanism price bundling in which payers allow a single payment for an episode of care leaving the physician and the hospital to negotiate over how the fee should be split modelling this as a nash bargaining game we cast doubt on the notion that price bundling can ensure cooperation and efficiency from the perspective of the players and suggest other incentives that may have led hospitals to participate in the experiment

identifying unmet demand brand preferences and marketplace demand are a reflection of the importance of underlying needs of consumers and the efficacy of product attributes for delivering value dog owners for example may look to dog foods to provide specific benefits for their pets e g shiny coats that may not be available from current offerings an analysis of consumer wants for these consumers would reveal weak demand for product attributes resulting from low efficacy despite the presence of strong latent interest the challenge in identifying such unmet demand is in distinguishing it from other reasons for weak preference such as general noninterest in the category and heterogeneous tastes we propose a model for separating out these effects within the context of conjoint analysis and we demonstrate its value with data from a national survey of toothpaste preferences implications for product development and reformulation are explored

implementing managerial constraints in model based segmentation extensions of kim fong and desarbo 2012 with an application to heterogeneous perceptions of service quality researchers have recently introduced a finite mixture bayesian regression model to simultaneously identify consumer market segments heterogeneity and determine how such segments differ with respect to active regression coefficients variable selection this article introduces three extensions of this model to incorporate managerial restrictions constraints the authors demonstrate with synthetic data that the new constrained finite mixture bayesian regression models can be used to identify and represent several constrained heterogeneous response patterns commonly encountered in practice in addition they show that the proposed models are more robust against multicollinearity than traditional methods finally to illustrate the proposed models usefulness the authors apply the proposed constrained models in the context of a service quality servperf survey of national insurance company s customers

bargaining power fear of disagreement and wage settlements theory and evidence from u s industry the paper develops and estimates a theoretical model of wage determination and union nonunion wage differentials in order to overcome the institutional ctiticisms of the formal bargaining literature the paper generalizes the nash zeuthen harsanyi model by linking the solution to the institutional concepts of bargaining power and fear or cost of disagreement and by making the outcome depend not only on endogenous but also on exogenous factors an operational specification of bargaining power and fear of disagreement allows the model to be estimated with data covering twelve companies and trade unions during the period from mid 1950 s to the late 1970 s while giving limited support to the nashzeuthen harsanyi solution the empirical analysis indicates that the bargaining outcome usually deviates from the nash zeuthen harsanyi point and in accordance with the institutionalist claim that it varies significantly with exogenous factors contrary to the traditional labor economics view the results do not support the general conclusion that the bargaining solution lies on the marginal revenue product curve of labor instead the relevant coefficients suggest that for many firms and unions the outcome might be better characterized by the efficient contract vertical contract curve

capturing context sensitive information usage in choice models via mixtures of information archetypes abstractthe authors offer a new conceptualization and operational model of consumer choice that allows context sensitive information usage and preference heterogeneity to be separately and simultaneously captured thus transforming the axiom of full information use into a testable hypothesis a key contribution of the proposed framework is the integration of two previously disjointed and often antagonistic research paradigms 1 the economic rationality perspective which assumes stable preferences and full information usage and 2 the psychological bounded rationality perspective which allows context sensitive preferences and information selectivity the authors demonstrate that the two paradigms can and do coexist in the same decision making space even at the level of individual consumer choices the proposed information archetype mixture model is tested in four studies that span different product categories and levels of task complexity the findings have ramifications for choice modeling theory a

sectoral money demand and the great disinflation in the united states estimates of the welfare costs of inflation based on bailey 1956 are typically computed using aggregate money demand models yet the behavior of money demand may vary across sectors thus the impact on welfare of inflation regime shifts may differ between households and firms we specifically investigate the sectoral welfare implications of the shift from the great inflation to the present regime of low and stable inflation for this purpose we estimate different functional specifications of money demand for u s households and nonfinancial firms using flow of fund data covering four decades we find that the benefits were significant for both sectors

hospital competition in hmo networks abstract we develop a framework for analyzing bargaining relationships between hospitals and hmos under selective contracting using a unique dataset on hospitals in the los angeles area from 1990 to 1993 we estimate the determinants of actual negotiated prices paid to hospitals by two major hmos we find that a hospital s bargaining power and thus its price decrease when the hmo can readily turn to alternative networks that exclude the hospital we simulate the effect of hypothetical hospital mergers on bargaining power and find that some hospital mergers even in urban areas with many nearby hospitals can lead to significant price increases

observed and unobserved preference heterogeneity in brand choice models this paper extends the scanner based choice literature by explicitly incorporating individual level brand preference data we illustrate our model using a unique data set that combines survey and scanner data collected from the same individuals the addition of individual specific brand preference information significantly improves fit and prediction furthermore this observed heterogeneity better explains choice than does unobserved heterogeneity in the standard scanner model s parameters more importantly we find that the standard model underestimates the importance of consumers brand preferences and overestimates both brand loyalties and price sensitivities brand loyalty is overestimated because models without preference information confound state dependence heterogeneity and preference effects price sensitivities are inflated because the average preference based consumer is implicitly assumed to be more willing to switch from his preferred brand than is the real preference based consumer further standard models overestimate the heterogeneity in price and loyalty sensitivities and misidentify both price and loyalty sensitive consumers the managerial implications of our findings and the applicability of our methodology when survey data are collected infrequently and for only a subsample of consumers are pursued we demonstrate that even under these circumstances better populationwide pricing and promotion decisions are identified and more accurate targeting results

insurer provider networks in the medical care market i use data on the hospital networks offered by managed care health insurers to estimate the expected division of profits between insurers and providers i include a simple profit maximization framework and an additional effect hospitals that can secure demand without contracting with all insurers e g those most attractive to consumers and those that are capacity constrained may demand high prices that some insurers refuse to pay hospital mergers may also affect price bargaining i estimate that all three types of hospitals capture higher markups than other providers these results provide information on the hospital investment incentives generated by bargaining

predicting joint choice using individual data choice decisions in the marketplace are often made by a collection of individuals or a group examples include purchase decisions involving families and organizations a particularly unique aspect of a joint choice is that the group s preference is very likely to diverge from preferences of the individuals that constitute the group for a marketing researcher the biggest hurdle in measuring group preference is that it is often infeasible or cost prohibitive to collect data at the group level our objective in this research is to propose a novel methodology to estimate joint preference without the need to collect joint data from the group members our methodology makes use of both stated and inferred preference measures and merges experimental design statistical modeling and utility aggregation theories to capture the psychological processes of preference revision and concession that lead to the joint preference results based on a study involving a cell phone purchase for 214 parent teen dyads demonstrate predictive validity of our proposed method

reality check combining choice experiments with market data to estimate the importance of product attributes discrete choice models estimated using hypothetical choices made in a survey setting i e choice experiments are widely used to estimate the importance of product attributes in order to make product design and marketing mix decisions choice experiments allow the researcher to estimate preferences for product features that do not yet exist in the market however parameters estimated from experimental data often show marked inconsistencies with those inferred from the market reducing their usefulness in forecasting and decision making we propose an approach for combining choice based conjoint data with individual level purchase data to produce estimates that are more consistent with the market unlike prior approaches for calibrating conjoint models so that they correctly predict aggregate market shares for a baseline market the proposed approach is designed to produce parameters that are more consistent with those that can be inferred from individual level market data the proposed method relies on a new general framework for combining two or more sources of individual level choice data to estimate a hierarchical discrete choice model past approaches to combining choice data assume that the population mean for the parameters is the same across both data sets and require that data sets are sampled from the same population in contrast we incorporate in the model individual characteristic variables and assert only that the mapping between individuals characteristics and their preferences is the same across the data sets this allows the model to be applied even if the sample of individuals observed in each data set is not representative of the population as a whole so long as appropriate product use variables are collected that can explain the systematic deviations between them the framework also explicitly incorporates a model for the individual characteristics which allows us to use bayesian missing data techniques to handle the situation where each data set contains different demographic variables this makes the method useful in practice for a wide range of existing market and conjoint data sets we apply the method to a set of conjoint and market data for minivan choice and find that the proposed method predicts holdout market choices better than a model estimated from conjoint data alone or a model that does not include demographic variables

skew and attribute non attendance within the bayesian mixed logit model abstract we investigate non attendance to choice set attributes and the accommodation of preference heterogeneity within the mixed logit model we propose a generalisation of the mixed logit enabling the degree of skew of marginal utility distributions to be estimated the implementation is bayesian with the marginal likelihood used as an arbiter of model performance we find strong evidence of skew in the distributions of marginal utilities for most attributes models incorporating skew are preferred in all cases the irrelevance of an attribute to significant numbers of respondents is a possible cause of such skew we test alternative empirical accommodations of self reported attribute non attendance ana and continue to find strong evidence of skew in the distributions of marginal utilities even having accounted for ana we find that contrary to some recent findings respondents who report having ignored an attribute typically do indeed have a zero marginal utility for that attribute

the effects of market structure and bargaining position on hospital prices ppos and hmos have gained widespread acceptance due in part to the belief that excess capacity and competitive market conditions can be leveraged to negotiate lower prices with health care providers we investigated prices obtained in different types of markets by the largest ppo in california our findings indicate that greater hospital competition leads to lower prices furthermore as the importance of a hospital to the ppo in an area increases the price rises substantially our testing of alternative methods for defining hospital geographic markets reveals that the common practice of using counties to define the market leads to an underestimate of the price increasing effects of a merger

contingent valuation of time spent on nhs waiting lists this paper derives estimates of the consumer bourne costs of waiting lists for nonurgent medical care the methodology used is contingent valuation the paper examines the use of this methodology and presents the experimental context and the estimates derived the estimates indicate the average valuation of a month spent on a waiting list for nonurgent care is approximately 40 pounds but also show that there exist significant interpersonal differences in valuations copyright 1990 by royal economic society

models for heterogeneous variable selection abstract preference heterogeneity is a major research stream in marketing aimed at quantifying and understanding the diversity of demand for product attributes and attribute levels in experimental settings in which consumers are presented with simple descriptions of product offerings continuous distributions of heterogeneity such as the multivariate normal provide a useful representation of preference however in more complex cases in which respondents have value for only a few of the benefits associated with an offering or cognitive constraints that result in selective attention to a subset of the information available continuous distributions of heterogeneity do not reflect the possibility that a subset of the variables has nonzero effect sizes for different respondents identifying which attributes are used in a brand choice decision is closely related to the statistical procedure of variable selection this article extends variable selection methods to accommodate heterogeneity across consumers

physician response to fee changes with multiple payers this paper develops a general model of physician behavior with demand inducement encompassing the two benchmark cases of profit maximization and target income behavior it is shown that when income effects are absent physicians maximize profits and when income effects are very strong physicians seek a target income the model is used to derive own and cross price expressions for the response of physicians to fee changes in the realistic context of more than one payer under the alternative behavior assumptions of profit maximization and target income behavior the implications for public and private fee policy and empirical research on physician response to fees are discussed

measurement of health state utilities for economic appraisal health status measurement for use in economic appraisal of health care programmes is reviewed in this paper with particular emphasis on utility measurement a framework for economic appraisal is presented displaying the various components that must be measured and showing how the three forms of analysis cost effectiveness analysis cost benefit analysis and cost utility analysis relate to the framework and to each other one of the components in the framework is health status it can be measured using ad hoc numeric scales willingness to pay receive or health state utilities the determination of health state utilities is reviewed covering the following issues alternative sources of utilities health state descriptions multi attribute utility approach determination of appropriate subjects utility aggregation and accuracy three measurement techniques for health state utilities are described in detail rating scale standard gamble and time trade off the use of these methods is described for both chronic and temporary health states and for both health states considered better than death and those considered worse than death

the welfare cost of inflation in general equilibrium abstract this paper presents a general equilibrium monetary model in which inflation distorts a variety of marginal decisions although individually none of the distortions is very large they combine to yield substantial welfare cost estimates a sustained 4 percent inflation like that experienced in the us since 1983 costs the economy the equivalent of 0 41 percent of output per year when currency is identified as the relevant definition of money and over 1 percent of output per year when m1 is defined as money the results illustrate how the traditional partial equilibrium approach can seriously underestimate the true cost of inflation

nash bargaining model of hmo premiums this paper estimates a model of commercial hmo premiums based on nash s axiomatic approach to bargaining between hmos and employers the bargaining models incorporate variables that measure the power of the parties to affect the division of potential gains from a contract it is found that an increase in the number of competing hmos increases the employer s bargaining power and leads to lower premiums especially for for profit hmos it is also found that employers bargaining power over non profit hmos is positively related to the ratio of the hmo s administrative expenses total expenses

monitoring choice task attribute attendance in nonmarket valuation of multiple park management services does it matter land management in alpine parks provides multifunctional services to separate groups of users choice experiments can be used to derive estimates of value for different management attri butes however little research has been conducted on how frequently respondents ignore attributes used to describe policy management scenarios we fill this gap using an approach that identifies and compares both serial and choice task attribute nonattendance addressing five different visitor types our results indicate that accounting for choice task nonatten dance significantly improves model fit and yield estimates of marginal willingness to pay with a more plausible pattern of signs and greater efficiency jel q24 q51 i introduction the effects of park management policies on outdoor recreation are increasingly coming under public scrutiny alpine park land is among the most valuable land in terms of outdoor recreation park manage ment decisions are often controversial be cause of differences between objectives pursued by conservationists and the tourist industry parkland management agencies find it increasingly difficult to fund all the services needed to facilitate the ever broad ening variety of outdoor recreation activi ties this is further exacerbated by the increasing expectations for high quality recreational experiences by a population of recreationists with a heightened sensitivity to environmental and conservation issues such a situation widens the scope for multiattribute nonmarket valuation meth ods especially for those methods capable of capturing and modeling the preferences of heterogeneous visitors who seek to pursue a variety of activities in the land under study our research reports the results of a study designed to address attribute nonattendance henceforth abbreviated as an a which despite being quite a common decision heuristic has only recently begun to be explored by analysts with this decision heuristic respondents ignore some of the described attributes in their evaluation of alternatives within a given choice task they hence act as if a zero weight were assigned to the ignored attributes in the utility of the respective alternatives we study this issue by using a well known statistical model of discrete choice the multinomial logit mnl model this random utility model is often used for the purpose of multi attribute nonmarket valuation but the effects of accounting for an a are still rela tively unexplored information on an a is commonly collected by questioning each respondent at the end of the sequence of choice tasks respondents are asked to list those attributes that they feel they have