Static Pricing Problems under Mixed Multinomial Logit Demand

Price differentiation is a common strategy for many transport operators. In this paper, we study a static multiproduct price optimization problem with demand given by a continuous mixed multinomial logit model. To solve this new problem, we design an efficient iterative optimization algorithm that asymptotically converges to the optimal solution. To this end, a linear optimization (LO) problem is formulated, based on the trust-region approach, to find a "good" feasible solution and approximate the problem from below. Another LO problem is designed using piecewise linear relaxations to approximate the optimization problem from above. Then, we develop a new branching method to tighten the optimality gap. Numerical experiments show the effectiveness of our method on a published, non-trivial, parking choice model

The flexible coefficient multinomial logit (FC-MNL) model of demand for differentiated products

We show FC-MNL is flexible in the sense of Diewert (1974), thus its parameters can be chosen to match a well-defined class of possible own- and cross-price elasticities of demand. In contrast to models such as Probit and Random Coefficient-MNL models, FC-MNL does not require estimation via simulation; it is fully analytic. Under well-defined and testable parameter restrictions, FC-MNL is shown to be an unexplored member of McFadden’s class of Multivariate Extreme Value discrete-choice models. Therefore, FC-MNL is fully consistent with an underlying structural model of heterogeneous, utility-maximizing consumers. We provide a Monte-Carlo study to establish its properties and we illustrate the use by estimating the demand for new automobiles in Italy

Measuring Network Effects in Mobile Telecommunications Markets with Stated‐Preference Valuation Methods

This paper demonstrates how stated-preference methods can be applied to modeling consumers' preferences in the field of mobile telecommunications, and to measuring and the valuation of network effects. We illustrate this with a case study of mobile phone operators in Poland. We utilize the Choice Experiment method and present the respondents with hypothetical choices of mobile phone operators, while explicitly controlling for network effects in the form of other users in the same network. Based on the hypothetical choices consumers make we construct a conditional random parameters multinomial logit model to analyze their preferences. This approach allows us to calculate welfare effects associated with alternatives, as well as marginal rates of substitution (and hence implicit prices) of the attributes used to describe the choices, such as operator brand and distribution of family and friends between available mobile networks. The latter constitutes a network effect as consumer's utility is influenced by the number (or ratio) of members of his or her family, friends and other users subscribed to the same operator. Our results confirm the existence of a strong network effect, which is related to the size of the social network group a particular subscriber belongs to, rather than the absolute size of the mobile operator's customer base. We observe that there are two sources of this 'gross' network effect - pecuniary (arising from possible price discounts for on-net calls) and non-pecuniary, and demonstrate a way to disaggregate them. In addition, we find that brand perception and brand loyalty are important determinants of operator choice. Finally, through the application of a non-market valuation method we are able to calculate monetary values of the network effect and brand loyalty, and both turn out to be relatively high. The results might be of a particular interest to mobile phone operators and regulatory authorities - we find that the capacity for vigorous price competition between mobile operators is limited due to significant non-price barriers which mitigate subscribers' mobility in the market. We demonstrate a way to measure these effects in monetary terms based on modeling of consumer preferences. --Network effects,mobile telecommunications,brand valuation,stated preference methods,non-market valuation methods,choice experiment,multinomial conditional logit model,preference heterogeneity,random parameters model

Price competition and the impact of service attributes: Structural estimation and analytical characterizations of equilibrium behavior

This dissertation addresses a number of outstanding, fundamental questions in operations management and industrial organization literature. Operations management literature has a long history of studying the competitive impact of operational, firm-level strategic decisions within oligopoly markets. The first essay reports on an empirical study of an important industry, the drive-thru fast-food industry. We estimate a competition model, derived from an underlying Mixed MultiNomial Logit (MNML) consumer choice model, using detailed empirical data. The main goal is to measure to what extent waiting time performance, along with price levels, brand attributes, geographical and demographic factors, impacts competing firms' market shares. The primary goal of our second essay is to characterize the equilibrium behavior of price competition models with Mixed Multinomial Logit (MMNL) demand functions under affine cost structures. In spite of the huge popularity of MMNL models in both the theoretical and empirical literature, it is not known, in general, whether a Nash equilibrium (in pure strategies) of prices exists, and whether the equilibria can be uniquely characterized as the solutions to the system of First Order Condition (FOC) equations. The third essay, which is the most general in its context, we establish that in the absence of cost efficiencies resulting from a merger, aggregate profits of the merging firms increase as do equilibrium prices for general price competition models with general nonlinear demand and cost functions as long as the models are supermodular, with two additional structural conditions: (i) each firm's profit function is strictly quasi-concave in its own price(s), and (ii) markets are competitive, i.e., in the pre-merger industry, each firm's profits increase when any of his competitors increases his price, unilaterally. Even the equilibrium profits of the remaining firms in the industry increase, while the consumer ends up holding the bag, i.e., consumer welfare declines. As demonstrated by this essay, the answers to these sorts of strategy questions have implications not only for the firms and customers but also the policy makers policing these markets

Imperfect Competition between Milk Manufacturers and Retailers in a Midwestern State in the U.S.

This manuscript studies the market conduct of the milk manufacturers and retail chains in a Midwestern state in the U.S. Following the menu approach we employ a random coefficient logit demand model to investigate several possible scenarios on the supply side. Demand estimates are obtained using both cross-sectional and time series variation in data. We also allow annual variation in consumer demographics which helps identify the coefficients of interaction between consumer demographics and product characteristics. To further enhance identification power we allow choice set of milk to vary across markets. The results are most supportive of the conjecture that manufacturers behave competitively letting the retailers be the residual claimants. Later they may collect a part or full rents from the retailers through two-part tariffs.Market conduct, random coefficient logit, vertical chain, imperfect competition, Agribusiness, Agricultural and Food Policy, Demand and Price Analysis, Industrial Organization, D43, L13,

Consumers and Experts: An Econometric Analysis of the Demand for Water Heaters

Consumers can accumulate product information on the basis of a combination of searching, product advertising and expert advice.Examples of experts who provide product information include doctors advising patients on treatments, motor mechanics diagnosing car problems and recommending repairs, accountants recommending investment strategies, and plumbers making recommendations on alternative water heaters.In each of these examples, the transactions involve the sale of goods and services where the seller is at the same time an expert providing advice on the amount and type of product or service to be purchased.In the case of water heaters, the plumber advising a consumer on their choice of water heater will most likely also install the appliance.Because of the information asymmetry there is potentially a strategic element in the transmission of information from expert to consumer.This paper reports on an econometric investigation of the factors that determine the choices made by consumers and the recommendations made by plumbers and the extent to which plumbers act in the best interests of their customers.The empirical work is made possible by the availability of stated preference data generated by designed experiments involving separate samples of Australian consumers and plumbers.We find some evidence that plumbers have higher preferences than consumers for heater characteristics that increase their profit margin.consumers;demand;product information;advertising;investment;econometrics

Policy Analysis in the Health-Services Market: Accounting for Quality and Quantity

We provide a theoretical and empirical framework for evaluating the effects of policy reforms on physician labor supply. We argue that any policy evaluation must account for both the quality and the quantity of services provided. The introduction of quality into the analysis has implications for both the theoretical and empirical analysis of labor supply, and consequently policy evaluation. In particular, endogenous quality choices introduce non-linearities into the budget constraint since the marginal return to an hour of work depends on the quality of services provided. We illustrate by considering a particular example: the recent reform in compensation contracts for specialist physicians in the province of Quebec (Canada). Prior to 1999, most Quebec specialist physicians were paid fee-for-service contracts; they received a piece rate for each clinical service provided. In 1999, the government introduced a mixed remuneration system, under which physicians received a base (half-daily or daily) wage, independent of services provided, and a reduced fee-for-service. Moreover, the government allowed physicians to choose their contract. We derive theoretical results for the effect of the reform on the quantity and quality of services supplied by analyzing "local" prices and virtual income. We propose discretizing the choice set as an empirical approach to policy evaluation in the presence of non-linear budget constraints.Health production, Quality of health services, Discretized models

Policy Analysis in the health-services market: accounting for quality and quantity

We provide a theoretical and empirical framework for evaluating the eects of policy reforms on physician labor supply. We argue that any policy evaluation must account for both the quality and the quantity of services provided. The introduction of quality into the analysis has implications for both the theoretical and empirical analysis of labor supply, and consequently policy evaluation. In particular, endogenous quality choices introduce non- linearities into the budget constraint since the marginal return to an hour of work depends on the quality of services provided. We illustrate by considering a particular example: the recent reform in compensation contracts for specialist physicians in the province of Quebec (Canada). Prior to 1999, most Quebec specialist physicians were paid fee-for-service con- tracts; they received a piece rate for each clinical service provided. In 1999, the government introduced a mixed remuneration system, under which physicians received a base (half-daily or daily) wage, independent of services provided, and a reduced fee-for-service. Moreover, the government allowed physicians to choose their contract. We derive theoretical results for the eect of the reform on the quantity and quality of services supplied by analyzing "local" prices and virtual income. We propose discretizing the choice set as an empirical approach to policy evaluation in the presence of non-linear budget constraints.Health production, Quality of health services, Discretized models