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Supply-Side Story: Risks, Guarantees, Competition, and Information Asymmetry

The risk of supply disruption increases as firms seek to procure from cheaper, but unproven, suppliers. We model a supply chain consisting of a single buyer and two suppliers, both of which compete for the buyers order and face risk of supply disruption. One supplier is comparatively more reliable but also more expensive, whereas the other one is less reliable but cheaper and faces higher risk of disruption. Moreover, the risk level of the unreliable supplier may be private information, and this lack of visibility increases the buyers purchasing risk. In such settings, the unreliable supplier often provides a price and quantity (P&Q) guarantee to the buyer. Our objective is to study the underlying motivation for the guarantee offer and its effects on the competitive intensity and the performance of the chain partners. Our model also includes a spot market that can be utilized by any party to buy or to sell. The spot market price is random, partially depends on the available capacity of the two suppliers, and has a positive spread between buying and selling prices. We analytically characterize the equilibrium contracts for the two suppliers and the buyers optimal procurement strategy. First, our analysis shows that P&Q guarantee allows the unreliable supplier to better compete against the more reliable one by providing supply assurance to the buyer. More importantly, when information asymmetry risk is high, use of a guarantee may enable the unreliable supplier to credibly signal her true risk, thereby improving visibility into the chain. This signal can also be used by the buyer to infer the expected spot market price. In spite of these benefits, a guarantee offer in an asymmetric setting may not always be desirable for the buyer. Rather, it can reduce competition between the suppliers, resulting in higher costs for the buyer. n nThis paper was accepted by Martin Lariviere, operations management.

Pricing and Manufacturing Decisions When Demand Is a Function of Prices in Multiple Periods

In most deterministic manufacturing decision models, demand is either known or induced by pricing decisions in the period that the demand is experienced. However, in more realistic market scenarios consumers make purchase decisions with respect to price, not only in the current period, but also in past and future periods. We model a joint manufacturing/pricing decision problem, accounting for that portion of demand realized in each period that is induced by the interaction of pricing decisions in the current period and in previous periods. We formulate a mathematical programming model and develop solution techniques. We identify structural properties of our models and develop closed-form solutions and effective heuristics for various special cases of our models. Finally, we conduct extensive computational experiments to quantify the effectiveness of our heuristics and to develop managerial insights.

OPTIMAL PROCUREMENT STRATEGY UNDER SUPPLY RISK

With the rapid expansion of global business, newer suppliers with cheaper but possibly unreliable technologies have entered the marketplace to win orders from buyer firms by beating the price of their perfectly reliable (but expensive) competitors. We model the procurement problem as a Nash game where the buyer has to allocate its purchases between an expensive but reliable supplier, and a cheaper but unreliable supplier. The suppliers specify prices for different proportions of the order awarded to them. Our analysis shows that, when perfect information is available about the reliability level of the unreliable supplier, the Nash equilibrium is a sole-sourcing allocation and that the supplier selection decision depends on the reliability and cost differentials between the two suppliers. In addition, we model the case when the buyer and the reliable supplier have limited information about the reliability of the unreliable supplier. Even in such an asymmetric scenario, the buyers equilibrium allocation is a sole-sourcing outcome, but depending on system conditions either a separating or a pooling equilibrium is possible. An interesting insight into the effect of information asymmetry is that it can result in higher or lower profits/costs for the channel partners (compared to the perfect information case). As such, the buyer may even benefit from information asymmetry regarding unreliable supplier due to its impact on the degree of competition between the two suppliers.

Returns Policies Between Channel Partners for Durable Products

Many durable products with relatively short selling seasons have been using returns policies between manufacturers and retailers as the contractual protocol for some time. Recently, these sectors have witnessed the growing popularity of peer-to-peer Web-based used goods markets as important transaction channels between buyers and sellers. Given that these two issues are critically linked from both supply and demand perspectives, in this paper we study the role that consumer valuation of used products plays in shaping a manufacturers incentive to offer a returns policy option to a retailer when used goods might be devalued compared to new ones as a result of physical deterioration or obsolescence. We do so through a two-period dyadic channel framework where the retailer faces uncertain demand for a durable product from a renewable set of customers who are impatient but forward looking. The manufacturer, on the other hand, needs to decide whether or not to offer a returns contract to the retailer. We first characterize the necessary and sufficient condition under which a returns contract is the equilibrium strategy as well as the corresponding channel decisions. Further analysis of this condition reveals that a higher consumer valuation of used products increases the likelihood of a returns contract being the equilibrium strategy. This result seems to be robust except when the potential demands for the two periods are quite deterministic and uncorrelated. However, it contradicts the burgeoning managerial trend to replace returns contracts with price-only ones in sectors where used goods are valued relatively highly by the consumers. We also discuss how used goods markets affect the equilibrium channel decisions as well as how demand uncertainty and logistics costs associated with returns influence the equilibrium contracting strategy.

With or Without Forecast Sharing: Competition and Credibility under Information Asymmetry

Forecast sharing among trading partners lies at the heart of many collaborative and contractual SCM efforts. Even though it has been praised in both academic and practitioner circles for its critical role in increasing demand visibility, some concerns remain: The first one is related to the credibility of forecast sharing, and the second is the fear that it may turn into a competitive disadvantage and induce suppliers to increase their price offerings. In this paper, we explore the validity of these concerns under a supply chain with a competitive upstream structure, focusing specifically on (i) when and how a credible forecast sharing can be sustainable, and (ii) how it impacts the intensity of price competition. To address these issues, we develop a supply chain model with a buyer facing a demand risk and two heterogeneous suppliers competing for order allocation from the buyer. The extent of the demand risk is known only to the buyer. The buyer submits a buying request to the suppliers via a commonly used procurement mechanism called request for quotation (RFQ). We consider two variants of RFQ. In the first type, the buyer simply shares the estimated order quantity with no further specifications. In the second one, in addition to this, the buyer also specifies minimum and/or maximum order quantities. We fully characterize equilibrium decisions and profits associated with them under symmetric and asymmetric information scenarios. Our main findings are that the buyer can use a RFQ with quantity restrictions as a credible signal for forecast sharing as long as the degree of demand information asymmetry is not too high, and that, contrary to above concerns, the equilibrium prices that emerge between competing suppliers under asymmetric information may indeed increase if the buyer cannot share forecast information credibly with its upstream partners.

Inventory, Discounts, and the Timing Effect

We introduce and analyze a model that explicitly considers the timing effect of intertemporal pricing---the concept, found in practice, that demand during a sale is increasing in the time since the last sale. We present structural results that characterize the interaction between the decision to hold a sale and the inventory-ordering decision. We show that the optimal inventory-ordering policy is a state-dependent base-stock policy; however, the optimal pricing policy can be quite complicated due to both the value and the cost of holding inventory and delaying sales. In our computational analysis, we find that compared to a fixed-price policy, we see an average gain in profit of almost 5% from optimally varying promotion and inventory decisions accounting for intertemporal demand, and we find that this potential profit gain increases as demand variability decreases. We also develop a heuristic based on deterministic pricing and find that it performs well relative to the optimal policy.

United We Stand or Divided We Stand? Strategic Supplier Alliances Under Order Default Risk

We study the alliance formation strategy among suppliers in a framework with one downstream firm and n upstream suppliers. Each supplier faces an exogenous random shock that may result in an order default. Each of them also has access to a recourse fund that can mitigate this risk. The suppliers can share the fund resources within an alliance, but they need to equitably allocate the profits of the alliance among the partners. In this context, suppliers need to decide whether to join larger alliances that have better chances of order fulfillment or smaller ones that may grant them higher profit allocations. We first analytically characterize the exact coalition-proof Nash-stable coalition structures that would arise for symmetric complementary or substitutable suppliers. Our analysis reveals that it is the appeal of default risk mitigation, rather than competition reduction, that motivates cooperation. In general, a riskier and/or less fragmented supply base favors larger alliances, whereas substitutable suppliers and customer demands with lower pass-through rates result in smaller ones. We then characterize the stable coalition structures for an asymmetric supplier base. We establish that grand coalition is more stable when the supplier base is more homogeneous in terms of their risk levels, rather than divided among a few highly risky suppliers and other low-risk ones. Going one step further, our investigation of endogenous recourse fund levels for the suppliers demonstrates how financing costs affect suppliers’ investments in risk-reducing resources and, consequently, their coalition formation strategy. Last, we discuss model generalizations and show that, in general, our insights are quite robust. This paper was accepted by Serguei Netessine, operations management.

A Single-Resource Revenue Management Problem with Random Resource Consumptions

We study a single-resource multi-class revenue management problem where the resource consumption for each class is random and only revealed at departure. The model is motivated by cargo revenue management problems in the airline and other shipping industries. We study how random resource consumption distribution affects the optimal expected profit and identify a preference acceptance order on classes. For a special case where the resource consumption for each class follows the same distribution, we fully characterize the optimal control policy. We then propose two easily computable heuristics: (i) a class-independent heuristic through parameter scaling, and (ii) a decomposition heuristic that decomposes the dynamic programming formulation into a collection of one-dimensional problems. We conduct extensive numerical experiments to investigate the performance of the two heuristics and compared them with several widely studied heuristic policies. Our results show that both heuristics work very well, with class-independent heuristic slightly better between the two. In particular, they consistently outperform heuristics that ignore demand and/or resource consumption uncertainty. Our results demonstrate the importance of considering random resource consumption as another problem dimension in revenue management applications.

On the value of terrorist’s private information in a government’s defensive resource allocation problem

The ability to understand and predict the sequence of events leading to a terrorist attack is one of the main issues in developing pre-emptive defense strategies for homeland security. This article, explores the value of terrorist’s private information on a government’s defense allocation decision. In particular, two settings with different informational structures are considered. In the first setting, the government knows the terrorist’s target preference but does not know whether the terrorist is fully rational in his target selection decision. In the second setting, the government knows the degree of rationality of the terrorist but does not know the terrorist’s target preference. The government’s equilibrium budget allocation strategy for each setting is fully characterized and it is shown that the government makes resource allocation decisions by comparing her valuation for each target with a set of thresholds. The Value Of Information (VOI) from the perspective of the government for each setting is derived. The obtained results show that VOI mainly depends on the government’s budget and the degree of heterogeneity among the targets. In general, VOI goes to zero when the government’s budget is high enough. However, the impact of heterogeneity among the targets on VOI further depends on whether the terrorist’s target preference matches those of the government’s or not. Finally, various extensions on the baseline model are performed and it is shown that the structural properties of budget allocation equilibrium still hold true.

Joint procurement and demand-side bidding strategies under price volatility

We consider a firm buying a commodity from a spot market as raw material and selling a final product by submitting bids. Bidding opportunities (i.e., demand arrivals) are random, and the likelihood of winning bids (i.e., selling the product) depends on the bid price. The price of the commodity raw material is also stochastic. The objective of the firm is to jointly decide on the procurement and bidding strategies to maximize its expected total discounted profit in the face of this demand and supply randomness. We model the commodity prices in the spot market as a Markov chain and the bidding opportunities as a Poisson process. Subsequently, we formulate the decision-making problem of the firm as an infinite-horizon stochastic dynamic program and analytically characterize its structural properties. We prove that the optimal procurement strategy follows a price-dependent base-stock policy and the optimal bidding price is decreasing with respect to the inventory level. We also formulate and analyze three intuitively appealing heuristic strategies, which either do not allow for carrying inventory or adopt simpler bidding policies (e.g., a constant bid price or myopically set bid prices). Using historical daily prices of several commodities, we then calibrate our models and conduct an extensive numerical study to compare the performances of the different strategies. Our study reveals the importance of adopting the optimal integrative procurement and bidding strategy, which is particularly rewarding when the raw material prices are more volatile and/or when there is significant competition on the demand side (the probability of winning is much smaller when submitting the same bid price). We establish that the relative performances of the three heuristic strategies depend critically on the holding cost of raw material inventory and the competitive environment, and identify conditions under which the shortfalls in profits from adopting such strategies are relatively less significant.