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

endogeneity in brand choice models applications of random utility models to scanner data have been widely presented in marketing for the last 20 years one particular problem with these applications is that they have ignored possible correlations between the independent variables in the deterministic component of utility price promotion etc and the stochastic component or error term in fact marketing mix variables such as price not only affect brand purchasing probabilities but are themselves endogenously set by marketing managers this work tests whether these endogeneity problems are important enough to warrant consideration when estimating random utility models with scanner panel data our results show that not accounting for endogeneity may result in a substantial bias in the parameter estimates

a heterogeneous conditional logit model of choice aggregate forecasts using mcfadden s conditional logit model of discrete choice harbor the unrealistic implicit assumption of a random utility distribution that is homogeneous across both alternatives and individuals this article relaxes that assumption a choice model is developed that describes the random utility component as a probability mixture model some numerical results illustrate that the derived model is not constrained by the independence of irrelevant alternatives property an experimental test of visual perceptions demonstrates the potential superiority of the model

a probabilistic choice model for market segmentation and elasticity structure marketing scholars commonly characterize market structure by studying the patterns of substitution implied by brand switching though the approach is useful it typically ignores the destabilizing

analysing the determinants of performance of best and worst european banks a mixed logit approach abstract using a dataset of 7635 observations on 1384 commercial banks operating in the eu between 1993 and 2001 we utilise a mixed logit model to identify factors that explain the probability of a bank being a best worst performer the empirical evidence confirms the importance of country level characteristics location and legal tradition and firm level features bank ownership balance sheet structure and size specifically smaller sized banks with higher loan intensity and foreign banks from countries upholding common law traditions have a higher probability of best performance

the impact of heterogeneity in purchase timing and price responsiveness on estimates of sticker shock effects the notion that individuals have an internal reference price against which they compare observed prices is well supported by several psychological theories empirically several papers in the marketing literature employing scanner panel data have modeled the impact of reference prices on brand choice via the sticker shock formulation in which consumers evaluate choice alternatives using differences between shelf prices and reference prices most of the studies reported thus far have not accounted for heterogeneity in price response among consumers and have typically imputed reference prices from the shelf prices of brands that a consumer is supposed to have observed on previous purchases in the category since category marketing activity can differentially affect the purchase timing of households we argue that this measure of reference price may follow certain systematic patterns across consumers and when combined with unaccounted for price response heterogeneity may result in a spurious sticker shock effect specifically we show that estimates of sticker shock are biased upward if households that are price sensitive in the brand choice decision are also more responsive to category promotion activity in their purchase timing decision we discuss some general conditions under which the bias occurs and conduct a simulation experiment to confirm our specific hypotheses our simulation results show that changes in purchase timing are a critical determinant of the bias in the sticker shock effect we also show that unaccounted for price response heterogeneity can in itself result in a biased sticker shock parameter however this requires very large differences in price sensitivities across consumers far greater than what is normally observed we develop a hierarchical bayes version of the nested logit model which models heterogeneity via individual level parameters in a continuous random effects framework we estimate the model on scanner panel data from the yogurt and ketchup categories we find in both categories that the 95 probability interval of the posterior distribution of the mean sticker shock coefficient contains the value zero therefore at least for the data used in this study there is no evidence for the sticker shock effect at the aggregate level in contrast the corresponding coefficient from a standard model which ignores this heterogeneity is highly significant and supports the existence of a possibly spurious sticker shock effect consistent with our explanation of the underlying cause of the bias households that are more price sensitive in the choice decision are also found to be more responsive to category promotion activity in their decision to purchase in the category the results highlight the measurement problems associated with imputing reference prices from past prices since the frequency duration and price level of a retailer s promotional program depend on its size and prevalence accurate estimates of the sticker shock effect are essential for formulating optimal promotion strategies an adequate accounting of consumer heterogeneity is critical to this effort

market oriented institutions and policies and economic growth a critical survey this paper surveys recent evidence suggesting that market oriented institutions and policies are strongly related to economic growth focusing on studies using the economic freedom ef indicator of the fraser institute this index is critically discussed also various serious shortcomings of empirical studies using this index are identified nevertheless there are strong indications that liberalization i e an increase in the ef index stimulates economic growth this paper also reviews studies on the determinants of ef political liberalization is often found to enhance economic liberalization whereas there is less evidence for causality running in the other direction

investigating heterogeneity in brand preferences in logit models for panel data in analyzing panel data the issue of heterogeneity across households is an important consideration if heterogeneity is present but is ignored in the analysis it will result in biased and inconsi

removing heterogeneity bias from logit model estimation this paper introduces a new estimation procedure for the logit model that is an extension of a conditional estimation procedure developed by chamberlain chamberlain g 1978 on the use of panel data working paper harvard university 1 52 chamberlain g 1980 analysis of covariance with qualitative data rev econom stud 47 225 238 the method eliminates heterogeneity bias which is present in the estimates produced by traditional estimation techniques it improves the goodness of fit and explanatory power of these models while incorporating purchase event feedback

a price discrimination theory of coupons the objective of this paper is to analyze the consumer s decision in electing to use cents off coupons distributed by manufacturers of consumer products arguing that the decision to use coupons is based on the tradeoff between costs of using coupons and the savings obtained it is shown that coupons can serve as a price discrimination device to provide a lower price to a particular segment of consumers based on a price theoretic model it is shown that the users of coupons are more price elastic than nonusers of coupons and that the opportunity cost of time and other household resource variables are determinant factors in consumers decisions implications derived from the model are tested using diary panel data

banks and regional development an empirical analysis on the determinants of credit availability in brazilian regions crocco m faria silva f paulo rezende l and rodriguez fuentes c j banks and regional development an empirical analysis on the determinants of credit availability in brazilian regions regional studies this paper studies the influence that liquidity preference and bank lending strategies might have played in the determination of bank credit availability in brazilian regions during the period 1999 2008 it puts forward the argument that in remoter and less developed regions the liquidity preference of agents is higher and fluctuates along business cycles reducing regional credit availability in downturns due to both a contraction in supply and the demand for credit in remoter regions and producing a more unstable pattern for credit availability alongside business cycles empirical evidence for the brazilian regions during the period 1999 2008 is provided to support this view

taste variation in discrete choice models this paper develops an extension of the classical multinomial logit model which approximates a class of models obtained when there is uncontrolled taste variation across agents and choices in addition to the stochastic noise inherent in the logit model unlike semiparametric and parametric alternatives the extended logit model is easy to estimate even when there are many potential choices unlike parametric alternatives it does not require the specification of a distribution of varying tastes the extended logit model can give a quick indication of the impact of taste variation on estimates and it generates estimates of the covariances of the taste shifters it can be used as an exploratory device en route to the construction of a model incorporating a particular form of random taste variation and it can be used to determine whether such effort is required at all when the amount of taste variation is not excessive the approximate model can be adequate itself the model nests the conventional logit model which leads to a misspecification diagnostic a method for estimating the model using conventional logit model software is proposed asymptotic properties of estimators are derived and an application is presented

note consumer store choice and choice set definition consumer store choice results from a process whereby information on various alternatives is evaluated by the consumer prior to the selection of one of these alternatives in the application of store choice models it is often assumed that the information processing strategy underlying store choice is a simultaneous one in which all possible alternatives are evaluated by an individual a competing assumption increasingly recognized in aspatial choice is that individuals initially evaluate clusters of alternatives and then only evaluate alternatives within a chosen cluster the nested logit model is a well known formulation for capturing this type of choice process this paper adds to the above understanding of consumer spatial choice in the following ways i it describes an alternative to the nested logit model known as a competing destinations model which can be used to model hierarchical spatial choice processes while this model has been described previously in the geography and planning literature this paper contains a novel derivation of it from within the random utility maximization framework ii a general choice formulation is derived from which the logit nested logit and competing destinations models can be obtained this allows the behavioral assumptions embedded in each model to be seen clearly and it allows a comparison of the nested logit and competing destinations formulations the latter is shown to be preferable in most spatial choice situations in particular the latter can be used when restricted choice sets are fuzzy iii the errors that arise when spatial choice results from a hierarchical process and when a simultaneous choice structure is assumed are demonstrated and are related to the presence of consumer competition agglomeration effects between stores which are thought to be important in store choice

latent homophily or social influence an empirical analysis of purchase within a social network consumers who are close to one another in a social network often make similar purchase decisions this similarity can result from latent homophily or social influence as well as common exogenous factors latent homophily means consumers who are connected to one another are likely to have similar characteristics and product preferences social influence refers to the ability of one consumer to directly influence another consumer s decision based upon their communication we present an empirical study of purchases of caller ring back tones using data from an asian mobile network that predicts consumers purchase timing and choice decisions we simultaneously measure latent homophily and social influence while also accounting for exogenous factors identification is achieved due to our dynamic panel data structure and the availability of detailed communication data we find strong influence effects and latent homophily effects in both the purchase timing and product choice decisions of consumers this paper was accepted by sandra slaughter information systems

parameter bias from unobserved effects in the multinomial logit model of consumer choice abstract over the past two decades validation of choice models has focused on predictive validity rather than parameter bias in real world validation of choice models true parameter values are unknown so examination of parameter bias is not possible in contrast the main focus of this study is parameter bias in simulated scanner panel choice data with known parameter values study of parameter bias enables the assessment of a fundamental issue not addressed in the choice modeling literature the extent to which the logit choice model is capable of distinguishing unobserved effects that give rise to persistence in observed choices e g heterogeneity and state dependence although econometric theory provides some information about the causes of bias the extent of such bias in typical scanner data applications remains unclear the authors present an extensive simulation study that provides information on the extent of bias resulting from the misspecification of four unobserved effects that receive fr

modeling multiple sources of heterogeneity in multinomial logit models methodological and managerial issues we offer a framework to specify and estimate various sources of heterogeneity in multinomial logit brand choice models we let each brand specific intercept and each parameter of the explanatory variable vector vary randomly across households in addition we distinguish loyal households from the rest our results suggest that incorporating multiple sources of heterogeneity improves the model fit and suggests higher impact of marketing mix elements on brand choice we highlight the importance of incorporating multiple sources of heterogeneity the model we implement yields valuable managerial insights

a model of brand choice and purchase quantity price sensitivities many consumer decisions involve a discrete choice and a continuous outcome examples of such decisions are whether to own a home or rent one and how much to spend which brand of orange juice to buy and how many ounces to buy in cases like these the choice decision is typically modeled separately say using a logit model and the continuous outcomes modeled separately using regression analysis however the continuous outcomes may not be independent of the discrete choice and vice versa and modeling the two decisions independently can lead to inefficient choice parameter estimates and biased and inconsistent regression parameter estimates in this paper we present a methodology from the limited dependent variable literature to model the dependence between the choice and quantity decisions our substantive interest is in the role of price in the choice and quantity decisions when choosing among alternatives we argue that consumers consider prices of all the competitive brands in the quantity decision on the other hand only the price of the chosen alternative is expected to impact how much of the alternative is purchased the analysis of three brands using disaggregate level panel data strongly supports our hypothesis about the role of competitive prices in the choice and quantity decisions

reference effects of price and promotion on brand choice behavior when consumers are exposed to pricing and promotional activity by frequently purchased packaged goods they may develop expectations that are used as points of reference in evaluating future activi

accounting for heterogeneity and nonstationarity in a cross sectional model of consumer purchase behavior when calibrating a brand choice model cross sectionally a measure of brand loyalty is often introduced into the utility function to account for differences in utility across households and over time one of the most widely used measures of brand loyalty proposed by guadagni and little 1983 is an exponential smoothing model of past choice behavior by the household in this study we argue that the exponential smoothing model of brand loyalty cannot properly distinguish between sources of variation in utility due to heterogeneity across households and sources of variation due to nonstationarity within household over time we introduce a new measure of brand loyalty derived from a nonstationary dirichlet multinomial choice model in which heterogeneity and nonstationarity are handled distinctly

a simultaneous approach to the whether what and how much to buy questions consumer s purchase decisions of whether to buy what to buy and how much to buy are examined simultaneously based on a consumer utility maximization problem an unobservable threshold price about which a consumer pivots from nonpurchase to purchase can be deduced with any model specification the interrelationships between purchase decisions can be explicitly derived the model is applied to coffee purchasing data in addition by suppressing the nonpurchase options the model is compared with an alternative approach appearing in the marketing literature

endogeneity and individual consumer choice abstract in many markets there is likely to be correlation both across periods in terms of the choices of one consumer and across consumers in terms of their choices in each period the former is caused by consumer heterogeneity and the latter may be the result of demand common shocks across consumers furthermore if firms partially observe these common shocks their market decisions may end up being endogenous and correlated with the common shocks because researchers cannot typically fully observe consumer heterogeneity and the common shocks the estimation method must account for the endogeneity of firms decisions in this article the authors present a test for endogeneity under unobserved consumer heterogeneity and common shocks which is based on a quasi likelihood estimation method to estimate the model parameters consistently when endogenous firm behavior unobserved heterogeneity and common shocks are present the test examines the differences in general method of moments coefficient estima

predictive testing of consumer choice models not subject to independence of irrelevant alternatives the probabilistic modeling of the relationship between objective or perceived characteristics of multiattribute alternatives and consumer choice is receiving increased attention in marketing and ot

a model of balanced choice behavior in some product categories consumers appear to alternate among items in a consistent and purposeful though not entirely deterministic fashion such alternation occurs even in the absence of any apparent external influences on choice to explain such balanced choice behavior we present a model based upon the premise that past consumption influences the utility of items on subsequent choice occasions individuals may seek variety on certain product attributes and exhibit loyalty toward others the model specification yields a logit choice model which may be calibrated using consumption diary panel data at the individual or cross sectional level