Columbia Business School Research

This paper articulates and applies frameworks for examining whether consumption is excessive. We consider two criteria for the possible excessiveness (or insufficiency) of current consumption. One is an intertemporal utility-maximization criterion: actual current consumption is deemed excessive if it is higher than the level of current consumption on the consumption path that maximizes the present discounted value of utility. The other is a sustainability criterion, which requires that current consumption be consistent with non-declining living standards over time.

We propose a dynamic equilibrium model of asset prices and trading volume when agents face fixed transactions costs. We show that even small fixed costs can give rise to large "no-trade" regions for each agent's optimal trading policy. The inability to trade more frequently reduces the agents' asset demand and in equilibrium gives rise to a significant illiquidity discount in asset prices.

Most management advice today — whether it's from books or articles, prescribed in courses or by consultants — says that change is good and more change is better. Advice on how to change varies quite a bit, but it has three features in common: "Creative destruction" is its motto. "Change or perish" is its justification. And "No pain, no change" is its rationale for overcoming a purportedly innate human resistance to change. The overarching goal is to invent a spanking new future ahead of one's competitors.

One of the most controversial aspects of globalization is capital-market liberalization - not so much the liberalization of rules governing foreign direct inveestment, but those affecting short-term capital flows, speculative hot capital that can come into and out of the country. In the 1980s and 1990s, the IMF and the U.S.

Gallant, Hansen, and Tauchen (1990)Go show how to use conditioning information optimally to construct a sharper unconditional variance bound (the GHT bound) on pricing kernels. The literature predominantly resorts to a simple but suboptimal procedure that scales returns with predictive instruments and computes standard bounds using the original and scaled returns. This article provides a formal bridge between the two approaches. We propose an optimally scaled bound that coincides with the GHT bound when the first and second conditional moments are known.

Motivated by practices in customer contact centers, we consider a system that offers two modes of service: real-time and postponed with a delay guarantee. Customers are informed of anticipated delays and select their preferred option of service. The resulting system is a multiclass, multiserver queueing system with state-dependent arrival rates.

This paper considers a Markovian model of a service system motivated by communication and information services. The system has finite processing capacity and offers multiple grades of service. The highest priority users receive a "guaranteed" processing rate, while lower priority users share residual capacity according to their priority level and therefore may experience service degradation; hence the term "best effort." This paper focuses on performance analysis for this class of systems.

This paper has three objectives. First, we develop an equilibrium pricing model in which consumers have incomplete information about both product qualities and prices. Specifically, manufacturers can use high prices to signal high quality to uninformed consumers. Furthermore, prices of any given brand can vary geographically across retail outlets. We show that previous models are special cases of our model. Specifically, the hedonic regression model assumes that consumers have full information about all product qualities and prices.

We consider a Markovian model of a multiclass queueing system in which a single large pool of servers attends to the various customer classes. Customers waiting to be served may abandon the queue, and there is a cost penalty associated with such abandonments. Service rates, abandonment rates, and abandonment penalties are generally different for the different classes. The problem studied is that of dynamically scheduling the various classes.

In recent years there have been enormous changes in our technology, our economy, and our society. But has there been progress? From most economists the first reaction to this question is: Of course there must have been progress! After all, the growth of new technologies expands opportunity sets, what we can do, the amount of output per unit input. We can choose either to have more output, more goods and services, or to work less. However we make the choice, surely we are better off. But what, then, about the sweeping changes we associate with the phenomenon of globalization?

Negotiation scholars and practitioners have long noted the impact of face, or social image, concerns on negotiation outcomes. When face is threatened, negotiators are less likely to reach agreement and to create joint gain. In this paper, we explore individual differences in face threat sensitivity (FTS), and how a negotiator's role moderates the relationship of his or her FTS to negotiation outcomes. Study 1 describes a measure of FTS. Study 2 finds that buyers and sellers are less likely to reach an agreement that is in both parties' interests when the seller has high FTS.

Research on new product launches has focused on improving the initial go/no-go decision to reduce the probability of post-launch failure. However, early-period assessments are hampered by a lack of data to enable further prediction—the few periods of aggregate sales data available to marketers are not enough on which to base reliable predictions.

Everyone who has studied international equity returns has noticed the episodes of high volatility and unusually high correlations coinciding with a bear market. We develop quantitative models of asset returns that match these patterns in the data and use them in two quantitative asset allocation analyses. First, we show that the presence of regimes with different correlations and expected returns is difficult to exploit with within a global asset allocation framework focussed on equities. The benefits of international diversification dominate the costs of ignoring the regimes.

Studies of the relationship between human resource management and establishment performance have heretofore focused on the manufacturing sector. Using a unique longitudinal dataset collected through site visits to branch operations of a large bank, the author extends that research to the service sector. Because branch managers had considerable discretion in managing their operations and employees, the HRM environment could vary greatly across branches and over time. Site visits provided specific examples of managerial practices that affected branch performance.

The research for which George Akerlof, Mike Spence, and I are being recognized is part of a larger research program which, today, embraces hundreds, perhaps thousands, of researchers around the world. In this lecture, I want to set the particular work which was sited within this broader agenda, and that agenda within the broader perspective of the history of economic thought. I hope to show that Information Economics represents a fundamental change in the prevailing paradigm within economices.

Intertemporal aggregation results in a summarization of information and a natural delay in the release of information. We study a principal-agent model and show that intertemporal aggregation can be an optimal feature of a performance evaluation system. We then highlight subtleties associated with valuing additional information as the level of aggregation of existing information is varied.

Many Strategic Account Programs are disconnected from the firm's strategic objectives and market place realities. If the Strategic Account Program is not central to your company's strategy formulation and implementation processes, it will have difficulty securing active senior management sponsorship and support. The Strategic Account Program then degenerates into a sales program and salespeople have difficulty getting alignment and commitment from other company functions.

The present study sought to examine the relationship between managers' perceptions of employee motivation and performance appraisal by surveying managers and employees in three distinct cultural regions (North America, Asia, and Latin America) within a single global organization. Although the patterns of employee self-perceptions did not vary across the six countries sampled, three distinct cultural patterns emerged in the theories managers held about their subordinates.

Previously we demonstrated a method, Quantized Surface Complementarity Diversity (QSCD), of defining molecular diversity by measuring shape and functional complementarity of molecules to a basis set of theoretical target surfaces [Wintner E.A. and Moallemi C.C., J. Med. Chem., 43 (2000) 1993]. In this paper we demonstrate a method of mapping actual protein pockets to the same basis set of theoretical target surfaces, thereby allowing categorization of protein pockets by their properties of shape and functionality.

In this paper, we examine the relationship between people's actual interpersonal sensitivity (such as their ability to identify deception and to infer intentions and emotions) and their perceptions of their own sensitivity. Like prior scholars, we find the connection is weak or non-existent and that most people overestimate their social judgment and mind-reading skills. Unlike previous work, however, we show new evidence about who misunderstands their sensitivity and why.

The telecommunications industry is a fragmented market, characterized by a tremendous amount of customer heterogeneity. This paper shows how such customer heterogeneity dramatically affects nonlinear pricing strategies: (i) First, if there are unbalanced calling patterns between different customer types, networks make larger profits on the least attractive customers. In addition, the nature of the calling pattern substantially affects how networks discriminate implicitly between different customer types.

An American option grants the holder the right to select the time at which to exercise the option, so pricing an American option entails solving an optimal stopping problem. Difficulties in applying standard numerical methods to complex pricing problems have motivated the development of techniques that combine Monte Carlo simulation with dynamic programming. One class of methods approximates the option value at each time using a linear combination of basis functions, and combines Monte Carlo with backward induction to estimate optimal coefficients in each approximation.

Organizations worldwide use contact centers as an important channel of communication and transaction with their customers. This paper describes a contact center with two channels, one for real-time telephone service, and another for a postponed call-back service offered with a guarantee on the maximum delay until a reply is received. Customers are sensitive to both real-time and call-back delay and their behavior is captured through a probabilistic choice model. The dynamics of the system are modeled as an M/M/N multiclass system.

We consider a joint inventory-pricing problem in which buyers act strategically and bid for units of a firm's product over an infinite horizon. The number of bidders in each period as well as the individual bidders' valuations are random but stationary over time. There is a holding cost for inventory and a unit cost for ordering more stock from an outside supplier. Backordering is not allowed. The firm must decide how to conduct its auctions and how to replenish its stock over time to maximize its profits.

An optimal coupling is a bivariate distribution with specified marginals achieving maximal correlation. We show that optimal couplings are totally positive and, in fact, satisfy a strictly stronger condition we call the nonintersection property. For discrete distributions we illustrate the equivalence between optimal coupling and a certain transportation problem. Specifically, the optimal solutions of greedily-solvable transportation problems are totally positive, and even nonintersecting, through a rearrangement of matrix entries that results in a Monge sequence.

This paper surveys the literature on option pricing, from its origins to the present. An extensive review of valuation methods for European- and American-style claims is provided. Applications to complex securities and numerical methods are surveyed. Emphasis is placed on recent trends and developments in methodology and modeling.

This paper considers an overbooking problem with multiple reservation and inventory classes, in which the multiple inventory classes may be used as substitutes to satisfy the demand of a given reservation class (perhaps at a cost). The problem is to jointly determine overbooking levels for the reservation classes, taking into account the substitution options. Such problems arise in a variety of revenue management contexts, including multicabin aircraft, back-to-back scheduled flights on the same leg, hotels with multiple room types, and mixed-vehicle car rental fleets.

We present a simple model where a firm will commit to a strictly positive hurdle rate on investment proposals by managers even though the two parties are symmetrically informed about the investments' profitability. Facing a positive hurdle rate, a manager who derives partial benefits from the investment profits will have more incentive to collect information about the projects. The optimal hurdle rate trades off the benefit of more information with the cost of foregoing ex post positive Net Present Value (NPV) projects.

I propose an intertemporal precautionary saving model in which the agent's labor income is subject to (possibly correlated) shocks with different degrees of persistence and volatility. However, he only observes his total income, not individual components. I show that partial observability of individual components of income gives rise to additional precautionary saving due to estimation risk, the error associated with estimating individual components of income. This additional precautionary saving is higher, when estimation risk is greater.

Previous studies on international marketing have typically asked the question: "how is the demand characterized across countries?" Such analysis is then used to provide guidelines for firms to enter new markets and/or to allocate marketing resources across countries.

This article focuses on the role of threats in negotiations. Broadly speaking, a threat is a proposition that issues demands and warns of the costs of noncompliance. Even if neither party resorts to them, potential threats shadow most negotiations. Researchers have found that people actually evaluate their counterparts more favorably when they combine promises with threats rather than extend promises alone. Whereas promises encourage exploitation, the threat of punishment motivates cooperation.

Recommendations often play a positive role in the decision process by reducing the difficulty associated with choosing between options. However, in certain circumstances recommendations play a less positive and more undesirable role from the perspectives of both the recommending agent or agency and the person receiving the recommendation. Across a series of four studies, we explore consumer response when recommendations by experts and intelligent agents contradict the consumer's initial impressions of choice options.