Breaking the Cycle: How the News and Markets Created a Negative Feedback Loop in COVID-19
New research from CBS Professor Harry Mamaysky reveals how negativity in the news and markets can escalate a financial crisis.
New research from CBS Professor Harry Mamaysky reveals how negativity in the news and markets can escalate a financial crisis.
Adapted from “Global Value Chains in Developing Countries: A Relational Perspective from Coffee and Garments,” by Laura Boudreau of Columbia Business School, Julia Cajal Grossi of the Geneva Graduate Institute, and Rocco Macchiavello of the London School of Economics.
Adapted from “Online Advertising as Passive Search,” by Raluca M. Ursu of New York University Stern School of Business, Andrey Simonov of Columbia Business School, and Eunkyung An of New York University Stern School of Business.
This paper from Columbia Business School, “Meaning of Manual Labor Impedes Consumer Adoption of Autonomous Products,” explores marketing solutions to some consumers’ resistance towards autonomous products. The study was co-authored by Emanuel de Bellis of the University of St. Gallen, Gita Johar of Columbia Business School, and Nicola Poletti of Cada.
Co-authored by John B. Donaldson of Columbia Business School, “The Macroeconomics of Stakeholder Equilibria,” proposes a model for a purely private, mutually beneficial financial agreement between worker and firm that keeps decision-making in the hands of stockholders while improving the employment contract for employees.
At Columbia Business School, our faculty members are at the forefront of research in their respective fields, offering innovative ideas that directly impact the practice of business today. A quick glance at our publication on faculty research, CBS Insights, will give you a sense of the breadth and immediacy of the insight our professors provide.
As a student at the School, this will greatly enrich your education. In Columbia classrooms, you are at the cutting-edge of industry, studying the practices that others will later adopt and teach. As any business leader will tell you, in a competitive environment, being first puts you at a distinct advantage over your peers. Learn economic development from Ray Fisman, the Lambert Family Professor of Social Enterprise and a rising star in the field, or real estate from Chris Mayer, the Paul Milstein Professor of Real Estate, a renowned expert and frequent commentator on complex housing issues. This way, when you complete your degree, you'll be set up to succeed.
Columbia Business School in conjunction with the Office of the Dean provides its faculty, PhD students, and other research staff with resources and cutting edge tools and technology to help push the boundaries of business research.
Specifically, our goal is to seamlessly help faculty set up and execute their research programs. This includes, but is not limited to:
All these activities help to facilitate and streamline faculty research, and that of the doctoral students working with them.
Many queueing situations such as computer, communications and emergency systems have the feature that customers may require service from several servers at the same time. They may thus be delayed until the required number of servers is avialable and servers may be idle when customers are waiting. We consider general server-completion-time distributions and derive approximation methods for the computation of the steady-state distribution of the number of customers in queue as well as the moments of the waiting-time distribution. Extensive computational results are reported.
Many queueing situations such as computer, communications and emergency systems have the feature that customers may require service from several servers at the same time. They may thus be delayed until the required number of servers is avialable and servers may be idle when customers are waiting. We consider general server-completion-time distributions and derive approximation methods for the computation of the steady-state distribution of the number of customers in queue as well as the moments of the waiting-time distribution. Extensive computational results are reported.
We develop two efficient procedures for generating cost allocation vectors in the core of a minimum cost spanning tree (m.c.s.t.) game. The first procedure requires O(n 2) elementary operations to obtain each additional point in the core, wheren is the number of users. The efficiency of the second procedure, which is a natural strengthening of the first procedure, stems from the special structure of minimum excess coalitions in the core of an m.c.s.t. game.
This paper attempts to contribute to two rapidly growing branches in economic theory: asset pricing and “overlapping generations” models. The model is formulated and it is shown that equilibrium prices exist, and some of their properties are discussed. Then the model is applied to an asymmetric information environment to see if randomness in the number of informed agents could confuse the uninformed. Surprisingly, it could not.
This paper presents a successive approximation method for solving systems of nested functional equations which arise, e.g., when considering Markov renewal programs in which policies that are maximal gain or optimal under more selective discount — and average overtaking optimality criteria are to be found. In particular, a successive approximation method is given to find the optimal bias vector and bias-optimal policies. Applications with respect to a number of additional stochastic control models are pointed out.
How many patrol cars staffed with a single police officer are needed to provide equivalent police service to an existing system with n two-officer patrol cars? This question is explored for New York City using a multiple patrol car per call priority queueing model. It is shown that a one-officer patrol program is feasible, yet pitfalls exist which could adversely affect its performance. The paper details the process of data analysis and model building and emphasizes the subjective elements that remain in a highly technical OR study.
How many patrol cars staffed with a single police officer are needed to provide equivalent police service to an existing system with n two-officer patrol cars? This question is explored for New York City using a multiple patrol car per call priority queueing model. It is shown that a one-officer patrol program is feasible, yet pitfalls exist which could adversely affect its performance. The paper details the process of data analysis and model building and emphasizes the subjective elements that remain in a highly technical OR study.
We explain the observed negative relati between market value of firms and their fund raising activities. Ours is not a signalling model. The firm's objective is to maximize the present value of its income. Considerations of cash availability (liquidity) and unfolding of uncertainty drive our model. Income from operations is an important source of liquidity. Low earnings are associated with low liquidity. Whether earnings are low or not is known to some extent in advance of the realization itself.
Group planning practices of leading American and Australian manufacturing firms are compared and contrasted. Despite some differences, a broad pattern of similarity emerges across many elements of the planning systems.
Group planning practices of leading American and Australian manufacturing firms are compared and contrasted. Despite some differences, a broad pattern of similarity emerges across many elements of the planning systems.
One of the primary concerns of urban police departments is the effective use of patrol cars. In large cities, police assigned to patrol cars typically account for more than 50% of total police manpower and their allocation has become particularly crucial in light of recent fiscal cutbacks.
The performance of adult females on information acquisition tasks is shown to be related to their performance on information integration tasks; both are shown to be related to basic measures of cognitive ability derived from formal operations theory.
In this paper, we analyze the behavior of equilibrium real interest rates in an identical consumer economy in which the preferences are represented by time additive logarithmic utility functions and production technologies are Cobb-Douglas with stochastic constant returns to scale. The following main results are established. (i) When there is no relative price uncertainty, it is shown that the equilibrium interest rate exhibits a mean reverting tendency. A nontrivial steady state distribution is found to exist for the equilibrium interest rate.
In many practical applications of multi-item inventory systems significant economies of scale can be exploited when coordinating replenishment orders for groups of items. This paper considers a continuous review multi-item inventory system with compound Poisson demand processes; excess demands are backlogged and each replenishment requires a lead time. There is a major setup cost associated with any replenishment of the family of items, and a minor (item dependent) setup cost when including a particular item in this replenishment. Moreover there are holding and penalty costs.
A reply correcting feedback from another economist. It explains in detail an aspect of the flotation cost adjustment.
We establish sufficient conditions for the recoverability and uniqueness of utility functions (preferences) generating consumption and asset demands in a two-period setting under uncertainty.
We address the combined problem of allocating a scarce resource among several locations, and planning deliveries using a fleet of vehicles. Demands are random, and holding and shortage costs must be considered in the decision along with transportation costs. We show how to extend some of the available methods for the deterministic vehicle routing problem to this case. Computational results using one such adaptation show that the algorithm is fast enough for practical work, and that substantial cost savings can be achieved with this approach.
We show that any triangulation of the 5-cube I5 by complete truncation, i.e., "slicing off" the even (or the odd) vertices, cannot use less than 67 or more than 68 pieces.
Consider a central depot that supplies several locations experiencing random demands. Periodically, the depot may place an order for exogenous supply. Orders arrive after a fixed leadtime, and are then allocated among the several locations. Each allocation reaches its destination after a further delay. We consider the special case where the penalty-cost/holding-cost ratio is constant over the locations. Several approaches are given to approximate the dynamic program describing the problem.
This paper presents an algorithm to compute an optimal (s,S) policy under standard assumptions (stationary data, well-behaved one-period costs, discrete demand, full backlogging, and the average-cost criterion). The method is iterative, starting with an arbitrary, given (s,S) policy and converging to an optimal policy in a finite number of iterations. Any of the available approximations can thus be used as an initial solution. Each iteration requires only modest computations. Also, a lower bound on the true optimal cost can be computed and used in a termination test.
Consider a central depot (or plant) which supplies several locations experiencing random demands. Orders are placed (or production is initiated) periodically by the depot. The order arrives after a fixed lead time, and is then allocated among the several locations. (The depot itself does not hold inventory.) The allocations are finally received at the demand points after another lag. Unfilled demand at each location is backordered. Linear costs are incurred at each location for holding inventory and for backorders. Also, costs are assessed for orders placed by the depot.
Clark and Scarf [1960] characterize optimal policies in a two-echelon, two-location inventory model. We extend their result to the infinite-horizon case (for both discounted and average costs). The computations required are far easier than for the finite horizon problem. Further simplification is achieved for normal demands. We also consider the more interesting case of multiple locations at the lower echelon. We show that, under certain conditions, this problem can be closely approximated by a model with one such location.
We examine a multi-server queueing system with Poisson arrivals in which customers require simultaneous service from a random number of servers. Servers assigned to the same customer begin and end service concurrently. Service times are, in general, assumed to be exponentially distributed. A system point approach is presented as a framework for obtaining the waiting time distribution for each customer type. Explicit solutions are derived for the two-server system.
In this paper we examine the effect of filing form 10-K on EDGAR on the incidence of small and large trades.
We focus on two commonly observed insurance policy provisions: upper limits on coverage and deductibles. We suggest that upper limits on coverage result from the effective limited liability obtained through the bankruptcy statutes. We show that absent moral hazard, if the administrative cost structure has fixed costs and scale economies, deductibles are not optimal. But the optimal contractual form leads to a moral hazard problem, which deductibles control.
This paper compares the properties of dividend announcements and management earnings forecasts as predictors of earnings and firm value. First, the two predictors are compared on the basis of their ability to predict earnings. Then the information they convey about firm value is assessed by comparison of the performance of investment strategies based on values of the two predictors. Finally, the effects of dividend announcements on stock prices are considered.
Corporate investment in an economy without a complete set of contingent claims markets has the characteristic of a public good in the sense that the stockholders' consumption plans cannot be separated from, but depend on, the specific investment plans of the firms. The purpose of this article is to develop an internal allocation mechanism capable of attaining production plans that are unanimously preferred by stockholders and that satisfy a natural notion of optimality applicable to the stock market economy.
This paper establishes the existence of a solution to the optimality equations in undiscounted semi-Markov decision models with countable state space, under conditions generalizing the hitherto obtained results. In particular, we merely require the existence of a finite set of states in which every pair of states can reach each other via some stationary policy, instead of the traditional and restrictive assumption that ever stationary policy has a single irreducible set of states.
Applied mathematical programming problems are often approximations of larger, more detailed problems. One criterion to evaluate an approximating program is the magnitude of the difference between the optimal objective values of the original and the approximating program. The approximation we consider is variable aggregation in a convex program. Bounds are derived on the difference between the two optimal objective values. Previous results of Geoffrion and Zipkin are obtained by specializing our results to linear programming. Also, we apply our bounds to a convex transportation problem.
In continuous review models with a fixed delivery lag T, the state of the system is conveniently described by the net inventory position = (inventory on hand) plus (outstanding orders), in spite of most cost components depending on the actual inventory on hand. To relate these two inventory concepts one observes that the distribution of the inventory on hand at time t + T is determined by the inventory position at time t.
This paper presents methods for solving allocation problems that can be stated as convex knapsack problems with generalized upper bounds. Such bounds may express upper limits on the total amount allocated to each of several subsets of activities. In addition our model arises as a subproblem in more complex mathematical programs. We therefore emphasize efficient procedures to recover optimality when minor changes in the parameters occur from one problem instance to the next. These considerations lead us to propose novel data structures for such problems.
The article focuses on the authors' comments on marketing of consumer information. Authors are somewhat distressed as their original article was severely misinterpreted by researcher Dan Sarel. Two main criticisms of the authors' model and methodology offered by Sarel are that the methodology cannot produce useful guidelines for three reasons: the criteria used in the methodology are inappropriate, the product is of a special nature and other important considerations have been omitted.
Evidence is given in this paper which indicates that corporate insiders time their trades in their firms' stock relative to the date of the disclosure of their forecasts of annual earnings. Further, insiders earn abnormal returns to their joint trading and information dissemination activities, and the paper provides measures of these returns.
Notwithstanding the apparent differences between convex games and minimum cost spanning tree (m.c.s.t.) games, we show that there is a close relationship between these two types of games. This close relationship is realized with the introduction of the group of permutationally convex (p.c.) games. It is shown that a p.c. game has a nonempty core and that both convex games and m.c.s.t, games are permutationally convex.
Suppose n facilities are to be located on a fine segment so as to minimize cost function. One might expect that the facilities' optimal locations have the following interleaving property: if one of the n facilities is removed and if the locations of the others are shifted by reoptimizing, each remaining facility's location shifts toward the location of the one removed, but not farther toward it than the original location of the adjacent facility. This paper presents two models whose solutions have this interleaving property and four examples of such models.
The recent appearance and growth of new delivery systems for dental services is examined from a marketing perspective. Analysis reveals that the growth of low priced, high throughput operations is consistent not only with marketing principles, but with the development of American retail institutions in general. Options for independent dentists in the face of this new competitive environment are discussed.
The article focuses on the author's view on whether consumers can calculate best buys. According to the author, a number of studies have found only a limited incidence of the ability to reason proportionately. Though subjects in these studies were still in their teens, little further development would be probable with their advancement into adulthood. This evidence led to their hypothesis that a significant number of adults would be unable to utilize a proportional reasoning strategy in a simple consumer decision-making context.