Multi‐Echelon Inventory Management under Short‐Term Take‐or‐Pay Contracts

We extend the Clark–Scarf serial multi‐echelon inventory model to include procuring production inputs under short‐term take‐or‐pay contracts at one or more stages. In each period, each such stage has the option to order/process at two different cost rates; the cheaper rate applies to units up to the contract quantity selected in the previous period. We prove that in each period and at each such stage, there are three base‐stock levels that characterize an optimal policy, two for the inventory policy and one for the contract quantity selection policy. The optimal cost function is additively separable in its state variables, leading to conquering the curse of dimensionality and the opportunity to manage the supply chain using independently acting managers. We develop conditions under which myopic policies are optimal and illustrate the results using numerical examples. We establish and use a generic one‐period result, which generalizes an important such result in the literature. Extensions to cover variants of take‐or‐pay contracts are included. Limitations are discussed.     

Green supply‐chain management: A state‐of‐the‐art literature review

There is a growing need for integrating environmentally sound choices into supply‐chain management research and practice. Perusal of the literature shows that a broad frame of reference for green supply‐chain management (GrSCM) is not adequately developed. Regulatory bodies that formulate regulations to meet societal and ecological concerns to facilitate growth of business and economy also suffer from its absence. A succinct classification to help academicians, researchers and practitioners in understanding integrated GrSCM from a wider perspective is needed. Further, sufficient literature is available to warrant such classification. This paper takes an integrated and fresh look into the area of GrSCM. The literature on GrSCM is covered exhaustively from its conceptualization, primarily taking a ‘reverse logistics angle’. Using the rich body of available literature, including earlier reviews that had relatively limited perspectives, the literature on GrSCM is classified on the basis of the problem context in supply chain's major influential areas. It is also classified on the basis of methodology and approach adopted. Various mathematical tools/techniques used in literature vis‐à‐vis the contexts of GrSCM are mapped. A timeline indicating relevant papers is also provided as a ready reference. Finally, the findings and interpretations are summarized, and the main research issues and opportunities are highlighted.     

No‐Betting‐Pareto Dominance

We argue that the notion of Pareto dominance is not as compelling in the presence of uncertainty as it is under certainty. In particular, voluntary trade based on differences in tastes is commonly accepted as desirable, because tastes cannot be wrong. By contrast, voluntary trade based on incompatible beliefs may indicate that at least one agent entertains mistaken beliefs. We propose and characterize a weaker, No‐Betting, notion of Pareto domination which requires, on top of unanimity of preference, the existence of shared beliefs that can rationalize such preference for each agent.     

Over‐the‐Counter Markets

We study how intermediation and asset prices in over‐the‐counter markets are affected by illiquidity associated with search and bargaining. We compute explicitly the prices at which investors trade with each other, as well as marketmakers' bid and ask prices, in a dynamic model with strategic agents. Bid–ask spreads are lower if investors can more easily find other investors or have easier access to multiple marketmakers. With a monopolistic marketmaker, bid–ask spreads are higher if investors have easier access to the marketmaker. We characterize endogenous search and welfare, and discuss empirical implications.     

SHORT‐TERM E‐PROCUREMENT STRATEGIES VERSUS LONG‐TERM CONTRACTS

In this paper we compare the following procurement strategies based on their expected costs: strategic partnership, which is based on a long‐term relationship with a single supplier; online search, which is a short‐term strategy; and a combined strategy, which is some combination of the first two strategies. In addition, we determine for the online search and combined strategy the optimal number of suppliers to contact for a price quote, and analyze how it depends on the various cost and demand parameters. The main contribution of this paper is that it does not assume a single procurement strategy, but rather compares three alternatives.     

An Analysis of Dual‐Kanban Just‐In‐Time Systems in a Non‐Repetitive Environment

Recent advances in approaches and production technologies for the production of goods and services have made just‐in‐time (JIT) a strong alternative for use in intermittent and small batch production systems, especially when time‐based competition is the norm and a low inventory is a must. However, the conventional JIT system is designed for mass production with a stable master production schedule. This paper suggests supplementing the information provided by production kanbans with information about customer waiting lines to be used by operators to schedule production in each work‐station of intermittent and small batch production systems. This paper uses simulation to analyze the effect of four scheduling policy variables—number of kanbans, length of the withdrawal cycle, information about customer waiting lines, and priority rules on two performance measures—customer wait‐time and inventory. The results show that using information about customer waiting lines reduces customer wait‐time by about 30% while also reducing inventory by about 2%. In addition, the effect of information about customer waiting lines overshadows the effect of priority rules on customer wait‐time and inventory.     

End‐of‐Sample Instability Tests

This paper considers tests for structural instability of short duration, such as at the end of the sample. The key feature of the testing problem is that the number, m, of observations in the period of potential change is relatively small—possibly as small as one. The well‐known F test of Chow (1960) for this problem only applies in a linear regression model with normally distributed iid errors and strictly exogenous regressors, even when the total number of observations, n+m, is large. We generalize the F test to cover regression models with much more general error processes, regressors that are not strictly exogenous, and estimation by instrumental variables as well as least squares. In addition, we extend the F test to nonlinear models estimated by generalized method of moments and maximum likelihood. Asymptotic critical values that are valid as n→∞ with m fixed are provided using a subsampling‐like method. The results apply quite generally to processes that are strictly stationary and ergodic under the null hypothesis of no structural instability.     

Hard‐to‐Solve Bimatrix Games

The Lemke–Howson algorithm is the classical method for finding one Nash equilibrium of a bimatrix game. This paper presents a class of square bimatrix games for which this algorithm takes, even in the best case, an exponential number of steps in the dimension d of the game. Using polytope theory, the games are constructed using pairs of dual cyclic polytopes with 2d suitably labeled facets in d‐space. The construction is extended to nonsquare games where, in addition to exponentially long Lemke–Howson computations, finding an equilibrium by support enumeration takes on average exponential time.     

New Product Design under Channel Acceptance: Brick‐and‐Mortar,Online‐Exclusive,or Brick‐and‐Click

In recent years, an increasing number of brick‐and‐mortar retailers have entered into the new brick‐and‐click era. Within this context, when a manufacturer presents a new product offering to a retailer, the ultimate decision is often made by the retailer regarding (1) whether to carry the new product, and (2) the channel outlet the product will be carried in (i.e., in‐store only, online‐exclusive, or brick‐and‐click). In response to this trend, we examine how a manufacturer may use product design to influence a dual‐channel retailer's outlet designation decision. This is the first study to investigate a manufacturer's optimal product design strategy when a brick‐and‐mortar retailer expands online. We demonstrate that, to induce the retailer to carry a new product both offline and online, it may not always be optimal for the manufacturer to enhance product quality (compared with when the retailer only operates offline). With the online store addition, the retailer may also be incentivized to adjust his participation criterion to a level less than what is determined by his outside option.     

Browse‐and‐Switch: Retail‐Online Competition under Value Uncertainty

Although online shopping is becoming popular, consumers who are unsure about whether to buy a product may find it advantageous to visit a brick‐and‐mortar retail store to first examine the product before purchasing it. But, after browsing at the store, consumers have the option of switching to an e‐tailer to purchase the item at a cheaper price rather than buying at the store. Recent business press refers to this browse‐and‐switch behavior as “showrooming,” and attributes to it the declining profits of brick‐and‐mortar retailers. To study the effect of the browse‐and‐switch option on retail and online pricing strategies and profits, we analyze a stylized economic model that incorporates uncertainty in consumers' valuation of the product, captures the heterogeneity among consumers in their inclination to purchase online, and permits product returns. We consider various equilibrium scenarios for different combinations of consumer shopping behaviors, characterize the parameter ranges for each scenario, and demonstrate that browse‐and‐switch behavior can indeed occur under equilibrium. Our analysis further shows that the option for consumers to browse‐and‐switch intensifies competition, reducing the profits for both firms.     

Optimal Production and Admission Policies in Make‐to‐Stock/Make‐to‐Order Manufacturing Systems

In this article, we study optimal production and admission control policies in manufacturing systems that produce two types of products: one type consists of identical items that are produced to stock, while the other has varying features and is produced to order. The model is motivated by applications from various industries, in particular, the automobile industry, where a part supplier receives orders from both an original equipment manufacturer and the aftermarket. The product for the original equipment manufacturer is produced to stock, it has higher priority, and its demands are fully accepted. The aftermarket product is produced to order, and its demands can be either accepted or rejected. We characterize the optimal production and admission policies with a partial‐linear structure, and using computational analysis, we provide insights into the benefits of the new policies. We also investigate the impact of production capacity, cost structure, and demand structure on system performance.     

A Study on a Sequential One‐Defender‐N‐Attacker Game

Government usually faces threat from multiple attackers. However, in the literature, researchers often model attackers as one monolithic player who chooses whether to attack, how much investment to spend, and on which target, instead of treating multiple attackers as independent agents. This modeling strategy may potentially cause suboptimal defense investment if the attackers have vastly different interests and preferences and may not be combined as one in theory. In this article, we develop a sequential game with complete information. This model considers one defender explicitly dealing with multiple unmergeable attackers. Thorough numerical experiments are conducted using ratio and exponential contest success functions under different scenarios. The result is also contrasted with the corresponding single attacker model to study the effect of mishandling multiple attackers. The propositions and observations drawn from the numerical experiments provide insights for government decision making with a better understanding of the attackers' behavior.     

Strategic Consumer Cooperation in a Name‐Your‐Own‐Price Channel

Supplier reluctance to openly advertise highly discounted products on the Internet has stimulated development of “opaque” name‐Your‐Own‐Price sales channels. Unfortunately (for suppliers), there is significant potential for online consumers to exploit these channels through collaboration in social networks. In this paper, we study three possible forms of consumer collaboration: exchange of bid result information, coordinated bidding, and coordinated bidding with risk pooling. We propose an egalitarian total utility maximizing mechanism for coordination and risk pooling in a bidding club and describe characteristics of consumers for whom participation in the club makes sense. We show that, in the absence of risk pooling, a plausible bidding club strategy using just information exchange gives almost the same benefits to consumers as coordinated bidding. In contrast, coordinated bidding with risk pooling can lead to significantly increased benefits for consumers. The benefits of risk pooling are highest for consumers with a low tolerance to risk. We also demonstrate that suppliers that actively adjust for such strategic consumer behavior can reduce the impact on their businesses and, under some circumstances, even increase revenues.     

LABOR‐ AND CAPITAL‐AUGMENTING TECHNICAL CHANGE

I analyze an economy in which firms can undertake both labor‐ and capital‐augmenting technological improvements. In the long run, the economy resembles the standard growth model with purely labor‐augmenting technical change, and the share of labor in GDP is constant. Along the transition path, however, there is capital‐augmenting technical change and factor shares change. Tax policy and changes in labor supply or savings typically change factor shares in the short run, but have no or little effect on the long‐run factor distribution of income. (JEL: O33, O14, O31, E25)     

TWO‐ AND THREE‐STAGE FLOWSHOP SCHEDULING WITH NO‐WAIT IN PROCESS

In this paper we study the time complexities of some two‐ and three‐stage no‐wait flowshop makespan scheduling problems where, in some stage, all the jobs require a constant processing time and the stage may consist of parallel identical machines. Polynomial time algorithms are presented for certain problems, while several others are proved to be strongly NP‐complete.     

Facilitating Redundancy‐Oriented Management with Gene‐Therapy‐Oriented Management Against Disaster

This article tests the hypothesis that “if redundancy‐oriented management has negative aspects, then it could be facilitated by gene‐therapy‐oriented management.” Negative aspects include disadvantages, misjudgments, or miscalculations. The article provides a newly revised principle of disaster management by studying gene‐therapy‐oriented management. Based on qualitative analysis, redundancy‐oriented and gene‐therapy‐oriented management are analyzed via five variables: governments, business, volunteers, households, and the international community. The article is valuable because an analytical frame on gene‐therapy‐oriented management is systematically reconceptualized for the field of disaster management via three elements: unhealthy proteins (problems or failed measures), a vector (new or modified solutions), and target cells (positive outcomes). In accepting the hypothesis, the key tenet is that stakeholders have to assist the progress of redundancy‐oriented management with gene‐therapy‐oriented management by paying attention to the genes of each disaster.     

Last‐In First‐Out Oligopoly Dynamics

This paper extends the static analysis of oligopoly structure into an infinite‐horizon setting with sunk costs and demand uncertainty. The observation that exit rates decline with firm age motivates the assumption of last‐in first‐out dynamics: An entrant expects to produce no longer than any incumbent. This selects an essentially unique Markov‐perfect equilibrium. With mild restrictions on the demand shocks, sequences of thresholds describe firms' equilibrium entry and survival decisions. Bresnahan and Reiss' (1993) empirical analysis of oligopolists' entry and exit assumes that such thresholds govern the evolution of the number of competitors. Our analysis provides an infinite‐horizon game‐theoretic foundation for that structure.     

PRODUCT OFFERING,PRICING, AND MAKE‐TO‐STOCK/MAKE‐TO‐ORDER DECISIONS WITH SHARED CAPACITY

In an era of mass customization, many firms continue to expand their product lines to remain competitive. These broader product lines may help to increase market share and may allow higher prices to be charged, but they also cause challenges associated with diseconomies of scope. To investigate this tradeoff, we considered a monopolist who faces demand curves, which for each of its potential products, decline with both price and response time (time to deliver the product). The firm must decide which products to offer, how to price them, whether each should be make‐to‐stock (mts) or make‐to‐order (mto), and how often to produce them. The offered products share a single manufacturing facility. Setup times introduce disceonomies of scope and setup costs introduce economies of scale. We provide motivating problem scenarios, model the monopolist's problem as a non‐linear, integer programming problem, characterize of the optimal policy, develop near‐optimal procedures, and discuss managerial insights.     

Single‐Period Two‐Product Assemble‐to‐Order Systems with a Common Component and Uncertain Demand Patterns

We consider a single‐period assemble‐to‐order system that produces two types of end products to satisfy two independent and stochastic customer orders. Each type of product is used to fulfill a particular customer order and these two products share a common component. Furthermore, one customer may confirm her order before the other one, and the manufacturer needs to make a commitment immediately upon the receipt of each customer order on how many products to be delivered. We propose a model for optimizing the inventory and production decisions under the above ATO environment. We also extend our model to the situation where the manufacturer can fulfill the unsatisfied low‐priority demand using the left‐over inventories after fulfilling the high‐priority demand, in case the low‐priority customer arrives first. Numerical experiments are conducted, which provide some interesting insights on the impact of uncertain demand pattern.     

EXPECTATIONS‐BASED REFERENCE‐DEPENDENT PREFERENCES AND ASSET PRICING

This paper explores the quantitative asset‐pricing implications of expectations‐based reference‐dependent preferences, as introduced by Koszegi and Rabin (2009, American Economic Review, 99(3), 909–936), in an otherwise traditional Lucas‐tree model. I find that the model easily succeeds in matching the historical equity premium and its variability when the preference parameters are calibrated in line with micro evidence. The equity premium is high because expectations‐based loss aversion makes uncertain fluctuations in consumption more painful. Additionally, loss aversion introduces variation in returns because unexpected cuts in consumption are particularly painful, and the agent wants to postpone such cuts to let his reference point decrease. This variation generates strong predictability. However, it also causes counterfactually high volatility in the risk‐free rate, which I address by allowing for variation in expected consumption growth, heteroskedasticity in consumption growth, time‐variant disaster risk, and sluggish belief updating.