Séminaires de Recherche

Examining the Impact of Ridehailing Services on Public Transit Use

Informations Systems and Operations Management

Intervenant : Gordon Burtch
Assistant Professor of Information Systems & Decision Sciences (Carlson School of Management - Minnesota University)

6 octobre 2017 - Salle Bernard Ramantsoa Bâtiment V - De 14h00 à 15h30


We examine the impact that ridehailing services (e.g., Uber, Lyft) have had on the use of various modes of public transportation in the United States, via a city-level analysis. We first evaluate these effects by exploiting the temporally and spatially staggered entry of Uber across the United States. Recognizing that the timing and location of Uber’s entry is likely to be endogenous with respect to dynamic variables that reflect a local economic environment, we introduce a novel time-series matching procedure that can deliver plausible identification under a difference-in-differences estimation framework. Subsequently, we re-evaluate the effects by exploiting a natural experiment in which the Google Maps application incorporated Uber and Lyft services into its transit / direction recommendations. Under both identification strategies we find consistent results. Our estimates indicate that ridehailing service entry has lead to significant reductions in the utilization of road-based, short-haul public transit services (e.g., bus), yet increased utilization of rail-based and long-haul transit services (e.g., subway, commuter rail). Finally, we show that resulting cannibalization and complementarity effects are attenuated and amplified, respectively, by transit agencies’ quality of service.

Short Bio:

Gord is an Assistant Professor of Information & Decision Sciences and Jim & Mary Lawrence Fellow at the University of Minnesota's Carlson School of Management, as well as a Consulting Researcher with Microsoft Research NYC. His research, which focuses on the economic evaluation of information systems, employs empirical analyses rooted in econometrics and field experimentation to identify and quantify the drivers of individual participation in online social contexts. His work has been published in a variety of top tier outlets, including Management Science, Information Systems Research, MIS Quarterly. In 2014, Gord won the ISR best paper award, and in 2016 he won the ISR best reviewer award. He holds a PhD from Temple University’s Fox School of Business, as well as Bachelor of Engineering and MBA degrees from McMaster University’s DeGroote School of Business

Heterogeneity of Reference Effects in the Competitive Newsvendor Problem

Informations Systems and Operations Management

Intervenant : Anton Ovchinnikov
Associate Professor & Distinguished Professor of Management Science & Operations Management , Smith School of Business, Queen‘s University

24 mars 2017 - Salle Bernard Ramanantsoa (Bâtiment V) - De 11h00 à 12h30


​This paper examines two recently-proposed reference effect formulations for the newsvendor problem and extends them to a competitive setting. The analysis of the resultant game shows that the heterogeneity of newsvendors’ reference effects can explain multiple regularities observed in recent experimental studies of newsvendor competition. Specifically, the observations that a behavioral newsvendor may effectively ignore the orders of the competitor, receive a significantly smaller profit, and over-order when there is no expected demand overflow can all be attributed to the heterogeneous reference effects in our model’s equilibrium. ​

Improving Environment, Health and Safety in Supply Chains: Some Preliminary Studies

Informations Systems and Operations Management

Intervenant : Christopher S. Tang
Carter Professor of Business Administration, , UCLA Anderson School

17 mars 2017 - Salle Bernard Ramanantsoa - De 11h00 à 12h30


Many factories in developing countries have serious Environment, Health and Safety (EHS) issues. Due to inconsistent law enforcement, limited progress has been made. What can be done? This is an open research topic that operations management and supply chain researchers should explore. I plan to share some of my preliminary studies in this presentation.

Consumer Choice Under Limited Attention and Implications on Firm Decisions

Informations Systems and Operations Management

Intervenant : Tamer Boyaci
Professor of Management Science, the Michael Diekmann Chair in Management Science, and Director of Research, , ESMT Berlin

3 mars 2017 - Salle Bernard Ramanantsoa - De 11h00 à 12h30


Facing an abundance of product choices and related information, but with only limited time and attention to evaluate them, consumers have to come to grips with how much and what type of information to pay attention to (and what to ignore), and make product choice and purchase decisions based on this partial information.
Evidently, it is often times easier to obtain information about some products then others (by the very nature of the product or simply because it is offered in an assortment and readily observable, among other reasons). At the same time there may be similarities (i.e., correlations) among products such that as the customer learns about a particular product, he/she may do so about another one.

Utilizing rational inattention theory, we present a general discrete choice model that describes the choice behavior of customers who optimally acquire information about available options with ex-ante uncertain values through potentially different channels with different costs. Customers trade-off the benefits of better information obtained by asking questions (and receiving informative signals) with the associated cost. We quantify acquired information and its cost through a novel function based on (Shannon) mutual information. Solving the consumer’s choice problem, we analytically characterize the resulting optimal choice behaviour. Some special cases of this model (including the generalized multinomial choice) are analyzed to illustrate key properties.

We then turn our attention to the applications of this choice model to business operations. We study assortment decisions of a seller as well as pricing decisions, demonstrating the implications of salient factors such as limited attention, cost of information, and correlations among products. Finally, we show how limited time and attention shapes the learning behaviour of the seller and its ordering strategies in a newsvendor setting.

A Markovian Approach to Choice Modeling and Assortment Optimization

Informations Systems and Operations Management

Intervenant : Antoine Desir
5th year PhD candidate - Industrial Engineering and Operations Research , (Columbia University, USA)

20 février 2017 - Salle Bernard Ramanantsoa (Bâtiment V) - De 10h30 à 12h00


Which set of products should be offered to arriving consumers to maximize expected revenue? This is a core revenue management problem known as assortment optimization which applies to a wide variety of settings. Discrete choice model theory offers a way to mathematically model the substitution behavior of consumers and provide a key ingredient for this problem. Many choice models have been proposed in the literature, introducing a fundamental tradeoff between model expressiveness and computational complexity. In particular, the assortment optimization problem is notoriously hard for general choice models. In this talk, we look at a new framework which tries to strike a good balance between expressiveness and tractability. In particular, the substitution behavior of consumers is modeled as transitions in a Markov chain. By doing so, this new model helps alleviate the Independence of Irrelevant Alternatives (IIA) property, a well-known limitation of the popular multinomial logit model. Moreover, it provides a good approximation to the class of random utility models. We show that not only this model has a great predictive power, it is also tractable from a computational perspective. In particular, we give a algorithm framework to derive efficient algorithm for different variants of the assortment optimization problem.

Merchant Operations of Energy Trading Networks

Informations Systems and Operations Management

Intervenant : Nicola Secomandi
Professor of Operations Management , Carnegie Mellon University, Pittsburgh

13 janvier 2017 - Salle Bernard Ramanantsoa - De 11h00 à 12h30


This talk provides an overview of the management of the operations of merchant companies that trade energy in networks of interconnected physical assets. It presents the business setting, introduces business analytics models that these firms can use to support their trading activities, and discusses modeling challenges that arise in practice, comparing different approaches from the perspective of model error. Specific examples include trading around natural gas transport and storage assets.

Revenue Management in Face of Choice Heterogeneity

Informations Systems and Operations Management

Intervenant : Ali Aouad
PhD candidate at MIT

16 décembre 2016 - Salle Bernard Ramanantsoa - Bâtiment V - De 10h30 à 12h00


Modern-day applications in e-commerce and brick-and-mortar retailing involve complex customer choice behaviors. Modeling this choice heterogeneity strikes a delicate balance between explaining large-scale data and prescribing efficient operational policies. At the strategic level, for the assortment selection problem, we propose a "consider-then-choose" modeling approach, borne out by the marketing literature. Experiments on a large purchase panel dataset demonstrate the strong predictive power of our models against common benchmarks. We develop a dynamic programming framework and show that many empirically vetted assumptions on how customers consider and then choose lead to tractable optimization models. Our algorithm dominates state-of-the-art commercial solvers in several regimes. Further, at the operational level, we study joint assortment and inventory management where customers show a dynamic substitution behavior. We derive the first provably good policies by revealing hidden submodular-like structure. Our approach is an order of magnitude faster than existing heuristics and increases revenue by 6% to 12% in experiments.
This work is based on several papers jointly with Profs. Vivek Farias, Retsef Levi and Danny Segev.

Internet adoption and knowledge diffusion

Informations Systems and Operations Management

Intervenant : Chris Forman
Professor from Cornell University (the IS department editor of Management Science)

5 décembre 2016 - Salle Bernard Ramanantsoa - Bâtiment V - De 10h30 à 12h00


What is the capacity of ICT to reduce the (geographical and technological) localization of knowledge? In this paper, we analyze the impact of Internet adoption within US firms on knowledge spillovers. More specifically, we investigate the impact of basic Internet access on the likelihood that patents invented at a given R&D establishment cite patents invented elsewhere within the same firm. Our findings suggest that adoption of Internet significantly fosters cross-location citations in a significant way, and that these effects are proportional to the technologically proximity of the establishments. This positive effect holds even when excluding collaborative patents or controlling for earlier collaborations, and suggests that Internet adoption has helped in reducing the spatial localization of knowledge but not in the ability to draw from new knowledge sources (i.e., across different technological areas).

Grocery Access, Market Structure and Food Waste

Informations Systems and Operations Management

Intervenant : Elena Belavina
Assistant Professor of Operations Management , University of Chicago

14 octobre 2016 - Salle Bernard Ramanantsoa (Bâtiment V) - De 10h30 à 12h00


This paper studies how access to grocery stores, and the extent and nature of competition in the grocery retail market influences food waste. Access to grocery, or how dense is the network of retail stores in a neighborhood, varies extensively as a result of zoning laws and other city government initiatives. Similarly, some markets are dominated by one chain, while others have a high degree of competition with a lot of independent grocery stores. And finally consumers in some markets are more price-sensitive, while in others the degree of product availability or service level is the key competitive variable. We build a multi-echelon arborescent supply chain model that includes heterogeneous customers each making optimal perishable inventory replenishment timing and level decisions in the face of demand uncertainty, as the lowest tiers. Competing grocery stores are the next tier, their demand arises as the superposition of the stochastic order processes of customers, and they themselves manage store inventories. We use these model to compute food waste and its dependence on store density and market structure.

My analysis reveals that, independent of the market structure, denser grocery store networks result in higher food waste at the store level, but lower consumer food waste, in contrast with the conventional wisdom that higher level of price competition would lead to higher consumer food waste due to resulting lower price of groceries. The conventional logic does not take into account the reduction in food waste due to increased convenience of grocery shopping. Overall, denser grocery store networks have lower food waste as consumer-side waste is substantially higher than waste at the store level. Further, keeping store density fixed, when price is main competitive dimension, market structures with low degree of competition (a single dominant chain) are more environmentally friendly than one with many individual retailers. On the other hand, when the main competitive dimension is service level, a higher degree of competition is preferred. That is, even without changing grocery store density by instilling the “right” competitive structure city governments can influence food waste levels.

"Your Action is Needed" : The effect of Website-Initiated Participation on User Contributions to Content Website

Informations Systems and Operations Management

Intervenant : Gal OESTREICHER-SINGER
Coller School of Management , Tel Aviv University

29 septembre 2016 - Salle Bernard Ramanantsoa (Bâtiment V) - De 03h00 à 05h00


Abstract
The success of contemporary content websites relies on users' active participation and contribution in the form of both social participation and payments. Recent research on website strategy and sustainability has found a link between users' social participation and users' willingness to pay for content-related services. However, website owners still find it challenging to elicit participation and payment behavior.
While previous research focused only on implicit encouragement to participate, we present website-initiated participation: the use of "Calls to Action" by the website that requires the user to perform participatory actions in order to consume content. We study the relation between website-initiated participation and users' willingness to contribute both effort and monetary funds. This approach is motivated by studies outside the context of online communities that suggest a link between short-term exogenously-initiated engagement and the resultant higher economic evaluation of the experience. We present a series of web experiments in a website called VideoBook that provides high-quality video content. While watching videos, users are presented with various prompts issued at different points in time, and their site behavior before and after exposure to these prompts is recorded.
Our first study shows that users who are given Calls to Action donate more money to the website compared with users who are not exposed to such prompts. We also show that even one prompt is enough to increase users' likelihood of voluntarily engaging with the website and to increase the number of contributions. The prompts do not affect users' enjoyment or willingness to continue using the website. Our second study, motivated by research on incremental engagement, shows that the sequence of participatory activities is also crucial; when the tasks that users are prompted to engage are presented in increasing order of effort level, users tend to donate and participate more than when tasks are not ordered. We extend our results by presenting a heterogeneity analysis that shows connection between the number of videos watched by the user and its susceptibility to website-initiated participation.

(this is joint work with Lior Zalmanson).


JavaScriptSettings