Research on auctions that involve more than one identical item for sale was,almost non-existing in the 90’s, but has since then been getting increasing attention. External incentives for this research have come from the US spectrum, sales, the European 3G mobile-phone auctions,  and Internet auctions. The policy relevance and the huge amount of money involved in many of them have helped the theory and experimental research advance. But in auctions where values are equal across bidders, common value auctions, that is, when the value depends on some outside parameter, equal to all bidders, the research is still embryonic. This thesis contributes to the topic with three studies. The first uses a Bayesian game to model a simple multi-unit common value auction, the task being to compare equilibrium strategies and the seller’s revenue from three auction formats; the discriminatory, the uniform and the Vickrey auction. The second study conducts an economic laboratory experiment on basis of the first study. The third study comprises an experiment on the multi-unit common value uniform auction and compares the dynamic and the static environments of this format. The most salient result in both experiments is that subjects overbid. They are victims of the winner’s curse and bid above the expected value, thus earning a negative profit. There is some learning, but most bidders continue to earn a negative profit also in later rounds. The competitive effect when participating in an auction seems to be stronger than the rationality concerns. In the first experiment, subjects in the Vickrey auction do somewhat better in small groups than subjects in the other auction types and, in the second experiment, subjects in the dynamic auction format perform much better than subjects in the static auction format; but still, they overbid. Due to this overbidding, the theoretical (but not the behavioral) prediction that the dynamic auction should render more revenue than the static fails inthe second experiment. Nonetheless, the higher revenue of the static auction comes at a cost; half of the auctions yield negative profits to the bidders, and the winner’s curse is more severely widespread in this format. Besides, only a minority of the bidders use the equilibrium bidding strategy.The bottom line is that the choice between the open and sealed-bid formats may be more important than the choice of price mechanism, especially in common value settings.

Future wireless networks will combine multiple radio technologies and subsystems, possibly managed by competing network providers. For such systems it may be advantageous to let the end nodes (terminals) make some or all of the resource management decisions. In addition to reducing complexity and costs, increasing redundancy, and facilitating more timely decisions; distributed resource sharing regimes can decouple the individual subsystems. Decoupled subsystems could be desirable both because competing operators can be business-wise separated and because it allows new technologies to be added (removed) in a modular fashion. However, distributed regimes can also lead to “selfish” wireless nodes who only try to maximize their own performance. The first part of this dissertation studies if selfish nodes can make efficient use of wireless resources, using multiaccess and network layers as examples. The related problems are formulated as noncooperative games between nodes. To maintain tractability nodes are confined to simple strategies that neither account for future payoffs nor allow for coordination. Yet, it is demonstrated that selfish nodes can achieve comparable performance to traditional protocols. These results should be interpreted as an argument in favor of distributed regimes. The second part of this dissertation evaluates the effects of multi-provider network architectures where users can roam freely across all networks. From a supply side perspective the benefits are improved path gain statistics and the fact that different networks may have non-overlapping busy hours. Several network configurations are analyzed and it is shown that cooperation between symmetric providers can yield significant capacity gains for both downlink and uplink; even if the providers have nearly collocated sites. When the providers have different site densities the gains from cooperation are reduced and the provider with a sparse network always gains more from cooperating. This suggests that initially, voluntary cooperation may be limited to some special cases. Lastly, the architecture is analyzed in a context where the providers compete for users on a per session basis by offering access at different prices. Although such architectures currently only exist in a few special cases, they could emerge in domestic markets where the costs to switch and search for new networks are low. Based on a game theoretic formulation it is shown that a competitive market for wireless access can be advantageous for both users and providers. The results presented suggest that the advantages of cooperation of competing providers occur in more than just a few cases. / QC 20100812

Abstract The modeling and analysis of multilateral negotiations are studied under the assumption that reaching an agreement is the main objective of the negotiators. A new methodology and associated definitions are proposed to predict the outcomes of such negotiations. The general objective of the new methodology is to study movements from one state to another in multilateral negotiations, to predict stable agreements, and to study their properties. The assumptions that the set of possible agreements is discrete and specified in advance make the negotiation problems considered here distinctive. Each decision maker has two concerns: first, achieving an alternative that is as preferable as possible; second, building support for this alternative among the other decision makers. In summary, this research consists of a systematic investigation of multilateral negotiations with the following general characteristics: • Decision makers in the negotiation seek a resolution that is not only feasible but also stable (enduring). Of course, each negotiator tries to attain the most preferable agreement for himself or herself. • If an agreement is reached, it must be an alternative from a pre-specified list, and all of the decision makers must accept the agreement. • Decision makers can possess different levels of power (or legitimacy) in support of an agreement, so the negotiation is not necessarily symmetric. Moreover, the analysis makes use of the decision makers’ preference orders over the proposed alternatives only, and does not require cardinal representations of their preferences. New concepts including State, Acceptability, Feasibility, Stability, and Fallback Distance are defined to pave the way for the proposed methodology. It is based on four types of movements, from unstable states toward stable ones, including preferential improvement, agglomeration, disloyalty move, and strategic disimprovement. Some criteria and algorithms are proposed to measure the likelihood of different moves and different outcomes. An important theorem shows that all four types of movement are mutually exclusive. The evolution of a negotiation from its status quo to the most likely outcomes is illustrated, using a tree. Several applications demonstrate that the proposed methodology can be applied to identify the most likely outcomes of a multilateral negotiation. Sensitivity analyses can be applied in several different ways to assess whether sudden or unforeseen changes in the model affect the conclusions. Several methods can be used from the literature for predicting the outcome of a negotiation. Social Choice Rules, Fallback Bargaining Procedures, and Bankruptcy Solutions are applied to the current negotiations over the legal status of the Caspian Sea to predict or recommend the most appropriate resolution among the proposed alternatives. In addition, the applicability of Graph Model for Conflict Resolution and its associated decision support system (DSS), GMCR II, are briefly discussed. Reasons why these methods are not appropriate when reaching an agreement is the main objective of decision makers (DMs) are then put forward. Based on the conceptual model for multilateral negotiations proposed in this thesis, a practical Negotiation Support System (NSS) is designed and implemented in Microsoft Access using Microsoft Visual Basic. This NSS increases the speed and accuracy of calculations. In the output of this NSS, all movements from initial states to subsequent states and their associated likelihoods are clearly illustrated, and all stable agreements are distinguished. Two real-world multilateral negotiations, over the legal status of the Caspian Sea and over the Epton site brownfield redevelopment project in Kitchener, Ontario, Canada, are modeled and analyzed using the proposed methodology. To measure DMs’ weights quantitatively in the Caspian Sea negotiations, eleven criteria that can be considered to be important determinants of countries’ capabilities are discussed, evaluated, and integrated using a Multiple Criteria Decision Analysis model. The Data Envelopment Analysis (DEA) method is employed to find the most favourable set of relative importance of different criteria for each country. Applying the proposed methodology indicates that unanimous agreements over the division of the Caspian Sea, either based on the International Law of the Seas or based on Soviet maps, are most likely as the enduring legal status of the Caspian Sea. The objective of applying the proposed methodology to actual negotiations over the redevelopment of a brownfield project is to ensure that the new methodology is flexible enough to model more real-world cases. Moreover, we wanted to test how well the actual outcomes of the real world negotiations match the most likely outcomes identified by the methodology. The results show that the decisions on the use of the Epton site followed the most likely path described and predicted by the model. This thesis is multidisciplinary in nature. It utilizes different branches of knowledge, including applied mathematics (game theory), computer science and programming, international relations, and environmental management. However, negotiation modeling and analysis in this thesis is developed from a systems engineering perspective.

This paper was developed from my reflections on an interdisciplinary critical making experiment in which I, visual artists, and computer programmers wrote, designed, and made a videogame, entitled Anathema, and a "Complete Companion" for the game that served as its booklet. I argue for the importance and continuing relevance of booklets and other textual objects accompanying videogames as there is no established scholarship on the topic and no ongoing debate or dialogue on the issue within the field of game studies. I demonstrate the ways that multiple modes of media, i.e. the game and its external objects, allow the narrative to break free of the individual media's constraints and overcome the perceived binary between mechanics-oriented and narrative-oriented videogames. I examine the evolution of booklets' roles in videogames by looking at key examples from early, millennial, and contemporary examples, including F-Zero, Diablo II, and the Mass Effect series. I also compare examples across genres, markets, and distribution methods, including independently produced and digitally distributed games. Finally, I draw on my own work on Anathema, the relationship between form and content within that project, and the role of the booklet therein to demonstrate the narrative and mechanical advantages of a multi-modal videogame. I conclude that while innovative mechanics can contribute to a multi-modal narrative in-game, the incorporation of both analogue and digital textual objects facilitates a more complete interaction with the art form.

Abstract The modeling and analysis of multilateral negotiations are studied under the assumption that reaching an agreement is the main objective of the negotiators. A new methodology and associated definitions are proposed to predict the outcomes of such negotiations. The general objective of the new methodology is to study movements from one state to another in multilateral negotiations, to predict stable agreements, and to study their properties. The assumptions that the set of possible agreements is discrete and specified in advance make the negotiation problems considered here distinctive. Each decision maker has two concerns: first, achieving an alternative that is as preferable as possible; second, building support for this alternative among the other decision makers. In summary, this research consists of a systematic investigation of multilateral negotiations with the following general characteristics: • Decision makers in the negotiation seek a resolution that is not only feasible but also stable (enduring). Of course, each negotiator tries to attain the most preferable agreement for himself or herself. • If an agreement is reached, it must be an alternative from a pre-specified list, and all of the decision makers must accept the agreement. • Decision makers can possess different levels of power (or legitimacy) in support of an agreement, so the negotiation is not necessarily symmetric. Moreover, the analysis makes use of the decision makers’ preference orders over the proposed alternatives only, and does not require cardinal representations of their preferences. New concepts including State, Acceptability, Feasibility, Stability, and Fallback Distance are defined to pave the way for the proposed methodology. It is based on four types of movements, from unstable states toward stable ones, including preferential improvement, agglomeration, disloyalty move, and strategic disimprovement. Some criteria and algorithms are proposed to measure the likelihood of different moves and different outcomes. An important theorem shows that all four types of movement are mutually exclusive. The evolution of a negotiation from its status quo to the most likely outcomes is illustrated, using a tree. Several applications demonstrate that the proposed methodology can be applied to identify the most likely outcomes of a multilateral negotiation. Sensitivity analyses can be applied in several different ways to assess whether sudden or unforeseen changes in the model affect the conclusions. Several methods can be used from the literature for predicting the outcome of a negotiation. Social Choice Rules, Fallback Bargaining Procedures, and Bankruptcy Solutions are applied to the current negotiations over the legal status of the Caspian Sea to predict or recommend the most appropriate resolution among the proposed alternatives. In addition, the applicability of Graph Model for Conflict Resolution and its associated decision support system (DSS), GMCR II, are briefly discussed. Reasons why these methods are not appropriate when reaching an agreement is the main objective of decision makers (DMs) are then put forward. Based on the conceptual model for multilateral negotiations proposed in this thesis, a practical Negotiation Support System (NSS) is designed and implemented in Microsoft Access using Microsoft Visual Basic. This NSS increases the speed and accuracy of calculations. In the output of this NSS, all movements from initial states to subsequent states and their associated likelihoods are clearly illustrated, and all stable agreements are distinguished. Two real-world multilateral negotiations, over the legal status of the Caspian Sea and over the Epton site brownfield redevelopment project in Kitchener, Ontario, Canada, are modeled and analyzed using the proposed methodology. To measure DMs’ weights quantitatively in the Caspian Sea negotiations, eleven criteria that can be considered to be important determinants of countries’ capabilities are discussed, evaluated, and integrated using a Multiple Criteria Decision Analysis model. The Data Envelopment Analysis (DEA) method is employed to find the most favourable set of relative importance of different criteria for each country. Applying the proposed methodology indicates that unanimous agreements over the division of the Caspian Sea, either based on the International Law of the Seas or based on Soviet maps, are most likely as the enduring legal status of the Caspian Sea. The objective of applying the proposed methodology to actual negotiations over the redevelopment of a brownfield project is to ensure that the new methodology is flexible enough to model more real-world cases. Moreover, we wanted to test how well the actual outcomes of the real world negotiations match the most likely outcomes identified by the methodology. The results show that the decisions on the use of the Epton site followed the most likely path described and predicted by the model. This thesis is multidisciplinary in nature. It utilizes different branches of knowledge, including applied mathematics (game theory), computer science and programming, international relations, and environmental management. However, negotiation modeling and analysis in this thesis is developed from a systems engineering perspective.

Transportation is important in making supply chain decisions. With the careful consideration of transportation expenses, the performance of each supply chain member, as well as the entire supply chain, could be improved significantly. The purpose of this research is: 1) to explore and identify the various situations that relate to replenishment and transportation activities; and 2) to reveal the strength of the connection between purchase quantity and transportation discounts, and integrate the two discounts to enhance supply-chain coordination. The problem is analyzed and categorized into four representative cases, depending on transportation. To aid the supplier or the carrier to determine the discount that should be offered, in light of the buyer's reaction to that discount, decision models are proposed under three different circumstances. First, assuming a single product, we investigate the quantity discounts from the supplier's perspective, via a noncooperative game-theoretical approach and also a joint decision model. Taking into account the price elasticity of demand, this analysis aids a sole supplier in establishing an all-unit quantity discount policy in light of the buyer's best reaction. The Stackelberg equilibrium and the Pareto-optimal solution set are derived for the noncooperative and joint-decision cases, respectively. Our research indicates that channel efficiency can be improved significantly if the quantity discount decision is made jointly rather than noncooperatively. Moreover, we extend our model in several directions: (a) the product is transported by a private fleet; (b) the buyer may choose to offer her customers a different percentage discount than that she obtained from the supplier; and (c) the case of multiple (heterogeneous) buyers. Numerical examples are employed, here and throughout the thesis, to illustrate the practical applications of the models presented and the sensitivity to model parameters. Secondly, we consider a situation with a family of SKUs for which the supplier will offer a quantity discount, according to the aggregate purchases of the product group. Management of those items is based on the modified periodic policy. From the supplier's point of view, what are the optimal parameters (breakpoint and discount percentage)? For deterministic demand, we discuss the cases in which demand is both constant and price-sensitive. First as a noncooperative Stackelberg game, and then when the two parties make the discount and replenishment decisions jointly, we illustrate the impact of price-sensitivity and joint decision making on the supplier's discount policy. The third approach studies the case in which transportation of the goods by a common carrier (a public, for-hire trucking company) is integrated in the quantity discount decisions. In reality, it is quite difficult for the carrier to determine the proper transportation discount, especially in the case of LTL (less-than-truckload) trucking. This is not only because of the "phantom freight" phenomenon, caused by possible over-declaration of the weight by the shipper, but also due to the fact that the discount relates to both transportation and inventory issues. In this research, we study the problem of coordinating the transportation and quantity discount decisions from the perspectives of the parties who offer the discounts, rather than the ones that take them. By comparison of the noncooperative and cooperative models, we show that cooperation provides better overall results, not only to each party, but also to the entire supply chain. To divide the extra payoffs gained from that cooperation, we further conduct a coalition analysis, based upon the concept of "Shapley Value." A detailed algorithm and numerical examples are provided to illustrate the solution procedure. Finally, the thesis concludes with comprehensive remarks. We summarize the contributions of this thesis, show the overall results obtained here, and present the directions that our research may take in the future.

<p>This dissertation uses game-theoretic modeling, statistical testing, and case studies to analyze how authoritarian governments manage the news media to maintain regime stability, control local officials, and make reform. In the first essay, ``Regime Competence and Media Freedom in Authoritarian States'', I explain why some authoritarian regimes allow more media freedom than others, as they tradeoff increased rents when the media is suppressed with the reduced risk of being misjudged by citizens when the media is free. In the second essay, ``Local Media Freedom, Protest Diffusion, and Authoritarian Resilience'', I argue that media reports about citizen protests, which may lead to protest diffusion, do not necessarily destabilize authoritarian rule. If protests are targeted at local governments, the central government of an authoritarian regime can use media-induced protest cascades to force local officials to improve governance. In the last essay, ``Central Rhetoric and Local Reform in China'', I address the puzzle of why the Chinese government would furnish the state media with conservative and dogmatic rhetoric on the one hand and allow reform on the other, by showing that this strategy is used to control local governments' pace of reform.</p> / Dissertation

We consider a decentralized, two-echelon supply chain where the upper echelon --the supplier-- bears the inventory risk. To service the retailers, the supplier either keeps inventory reserved for each of her customers or else pools inventory to share among her customers. The common insight regarding inventory pooling is that it reduces costs and so increases profits for the supply chain party carrying inventory. However, it has recently been shown that inventory pooling may indeed reduce the total supply chain profits. We further show that inventory pooling may reduce supply chain profits even under traditional service contracts based on the frequently invoked measure of service, probability of stock-out. We model the inventory transactions among the retailers and the supplier as a cooperative game. The players have the option of reserving inventory or forming inventory-pooling coalitions. The total profit of the coalitions is allotted to the players using a profit-sharing mechanism based on Shapley value. We analyze the properties of the proposed profit-sharing scheme in two steps. We first consider a stylized model with two retailers who are not necessarily identical. Then we extend the analysis to an arbitrary number of identical retailers. In both cases, we assume the demand across retailers is independent. We find that the Shapley value allocations coordinate the supply chain and are individually rational. However for more than two retailers, they may not be in the core. Even when they satisfy all the stability properties, including membership in the core, they may be perceived unfair since a player's allocation can exceed his contribution to the total supply chain profit. In addition to analyzing the stability properties of the proposed allocation mechanism, we are also interested in the types of behavior the mechanism induces in the players. We find that the retailers prefer pooling partners with either very high or low service level requirements and the supplier prefers retailers with low service requirements since this gives her the ability to maximize her profit allocation. Finally, we analyze the effects of demand variance on the allocations and the profitability of strategic retailer coalitions.

This dissertation analyzes the economic incentives involved in three distinct supply chain and revenue management decision environments. The first study examines the adoption of the percent deviation contract in a supply chain to induce the buyer to share some of the demand risk in an environment in which the buyer would typically place her order when she has full knowledge of the customer demand levels. The subgame-perfect Nash Equilibrium decisions are characterized, and the percent deviation is shown to achieve full supply chain channel coordination in cases where a simpler contract cannot. Pareto-improving examples based on industry demand data are presented and discussed. The second section considers a revenue management problem for sports and entertainment organizations. Given that the organization starts the selling season by offering ticket packages exclusively, the optimal time during the selling season for the organization to begin selling individual-event tickets is derived. Extensions of the base model are developed to include multiple ticket packages and heterogeneous ticket packages. The model is illustrated using empirical data sets obtained from the Georgia Tech Athletic Department and the Atlanta Symphony Orchestra. The third section develops a model of vendor-controlled category management in which vendors are in charge of the stocking and assortment decisions for a given amount of shelf space at a vendor when the retailer retains control over the retail price. The subgame-perfect Nash Equilibrium strategies for two vendors and a single retailer are analyzed, and a revenue-sharing contract is shown to coordinate the channel when the vendors can produce multiple brands in a given product category and shelf space is sufficiently large or small.

As computer and communication networks become prevalent, the Internet has been a battlefield for attackers and defenders. One of the most powerful weapons for attackers is the Internet worm. Specifically, a worm attacks vulnerable computer systems and employs self-propagating methods to flood the Internet rapidly. The objective of this research is to characterize worm attack behaviors, analyze Internet vulnerabilities, and develop effective countermeasures. More specifically, some fundamental factors that enable a worm to be designed with advanced scanning methods are presented and investigated through mathematical modeling, simulations, and real measurements. First, one factor is an uneven vulnerable-host distribution that leads to an optimal scanning method called importance scanning. Such a new method is developed from and named after importance sampling in statistics and enables a worm to spread much faster than both random and routable scanning. The information of vulnerable-host distributions, however, may not be known before a worm is released. To overcome this, worms using two sub-optimal methods are then investigated. One is a self-learning worm that can accurately estimate the underlying vulnerable-host distribution while propagating. The other is a localized-scanning worm that has been exploited by Code Red II and Nimda worms. The optimal localized scanning and three variants of localized scanning are also studied. To fight against importance-scanning, self-learning, and localized-scanning worms, defenders should scatter applications uniformly in the entire IP-address space from the viewpoint of game theory. Next, a new metric, referred to as the non-uniformity factor, is presented to quantify both the unevenness of a vulnerable-host distribution and the spreading ability of network-aware worms. This metric is essentially the Renyi information entropy and better characterizes the non-uniformity of a distribution than the Shannon entropy. Finally, another fundamental factor is topology information that enables topological-scanning worms. The spreading dynamics of topological-scanning worms are modeled through a spatial-temporal random process and simulated with both real and synthesized topologies.