@inproceedings{112, abstract = {{We study a model of selfish resource allocation that seeks to incorporate dependencies among resources as they exist in in modern networked environments. Our model is inspired by utility functions with constant elasticity of substitution (CES) which is a well-studied model in economics. We consider congestion games with different aggregation functions. In particular, we study $L_p$ norms and analyze the existence and complexity of (approximate) pure Nash equilibria. Additionally, we give an almost tight characterization based on monotonicity properties to describe the set of aggregation functions that guarantee the existence of pure Nash equilibria.}}, author = {{Feldotto, Matthias and Leder, Lennart and Skopalik, Alexander}}, booktitle = {{Proceedings of the 10th International Conference on Algorithms and Complexity (CIAC)}}, pages = {{222----233}}, title = {{{Congestion Games with Complementarities}}}, doi = {{10.1007/978-3-319-57586-5_19}}, year = {{2017}}, } @inproceedings{113, abstract = {{We study the computation of approximate pure Nash equilibria in Shapley value (SV) weighted congestion games, introduced in [19]. This class of games considers weighted congestion games in which Shapley values are used as an alternative (to proportional shares) for distributing the total cost of each resource among its users. We focus on the interesting subclass of such games with polynomial resource cost functions and present an algorithm that computes approximate pure Nash equilibria with a polynomial number of strategy updates. Since computing a single strategy update is hard, we apply sampling techniques which allow us to achieve polynomial running time. The algorithm builds on the algorithmic ideas of [7], however, to the best of our knowledge, this is the first algorithmic result on computation of approximate equilibria using other than proportional shares as player costs in this setting. We present a novel relation that approximates the Shapley value of a player by her proportional share and vice versa. As side results, we upper bound the approximate price of anarchy of such games and significantly improve the best known factor for computing approximate pure Nash equilibria in weighted congestion games of [7].}}, author = {{Feldotto, Matthias and Gairing, Martin and Kotsialou, Grammateia and Skopalik, Alexander}}, booktitle = {{Proceedings of the 13th International Conference on Web and Internet Economics (WINE)}}, title = {{{Computing Approximate Pure Nash Equilibria in Shapley Value Weighted Congestion Games}}}, doi = {{10.1007/978-3-319-71924-5_14}}, year = {{2017}}, } @inproceedings{1767, abstract = {{Conditional Value-at-Risk, denoted as CVaRα, is becoming the prevailing measure of risk over two paramount economic domains: the insurance domain and the financial domain; α∈(0,1) is the confidence level. In this work, we study the strategic equilibria for an economic system modeled as a game, where risk-averse players seek to minimize the Conditional Value-at-Risk of their costs. Concretely, in a CVaRα -equilibrium, the mixed strategy of each player is a best-response. We establish two significant properties of CVaRα at equilibrium: (1) The Optimal-Value property: For any best-response of a player, each mixed strategy in the support gives the same cost to the player. This follows directly from the concavity of CVaRα in the involved probabilities, which we establish. (2) The Crawford property: For every α, there is a 2-player game with no CVaRα-equilibrium. The property is established using the Optimal-Value property and a new functional property of CVaRα, called Weak-Equilibrium-for- VaRα, we establish. On top of these properties, we show, as one of our two main results, that deciding the existence of a CVaRα-equilibrium is strongly NP-hard even for 2-player games. As our other main result, we show the strong NP-hardness of deciding the existence of a V-equilibrium, over 2-player games, for any valuation V with the Optimal-Value and the Crawford properties. This result has a rich potential since we prove that the very significant and broad class of strictly quasiconcave valuations has the Optimal-Value property.}}, author = {{Mavronicolas, Marios and Monien, Burkhard}}, booktitle = {{Proceedings of the 10th International Symposium on Algorithmic Game Theory (SAGT 2017)}}, location = {{L'Aquila, Italy}}, pages = {{131----143}}, title = {{{Conditional Value-at-Risk: Structure and Complexity of Equilibria}}}, doi = {{10.1007/978-3-319-66700-3_11}}, volume = {{10504}}, year = {{2017}}, } @article{2269, author = {{Mauleon, Ana and Roehl, Nils and Vannetelbosch, Vincent}}, issn = {{0899-8256}}, journal = {{Games and Economic Behavior}}, pages = {{135--152}}, publisher = {{Elsevier}}, title = {{{Constitutions and groups}}}, doi = {{10.1016/j.geb.2017.10.022}}, volume = {{107}}, year = {{2017}}, } @misc{83, author = {{Uden, Dennis}}, publisher = {{Universität Paderborn}}, title = {{{Microsoft vs. the EU Commission - An analysis on product bundeling}}}, year = {{2017}}, } @inproceedings{59, abstract = {{We consider a scheduling problem on $m$ identical processors sharing an arbitrarily divisible resource. In addition to assigning jobs to processors, the scheduler must distribute the resource among the processors (e.g., for three processors in shares of 20\%, 15\%, and 65\%) and adjust this distribution over time. Each job $j$ comes with a size $p_j \in \mathbb{R}$ and a resource requirement $r_j > 0$. Jobs do not benefit when receiving a share larger than $r_j$ of the resource. But providing them with a fraction of the resource requirement causes a linear decrease in the processing efficiency. We seek a (non-preemptive) job and resource assignment minimizing the makespan.Our main result is an efficient approximation algorithm which achieves an approximation ratio of $2 + 1/(m-2)$. It can be improved to an (asymptotic) ratio of $1 + 1/(m-1)$ if all jobs have unit size. Our algorithms also imply new results for a well-known bin packing problem with splittable items and a restricted number of allowed item parts per bin.Based upon the above solution, we also derive an approximation algorithm with similar guarantees for a setting in which we introduce so-called tasks each containing several jobs and where we are interested in the average completion time of tasks (a task is completed when all its jobs are completed).}}, author = {{Kling, Peter and Mäcker, Alexander and Riechers, Sören and Skopalik, Alexander}}, booktitle = {{Proceedings of the 29th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA)}}, pages = {{123----132}}, title = {{{Sharing is Caring: Multiprocessor Scheduling with a Sharable Resource}}}, doi = {{10.1145/3087556.3087578}}, year = {{2017}}, } @misc{5946, author = {{Kühn, Sarah}}, publisher = {{Universität Paderborn}}, title = {{{Outsourcing und Qualität im Supply Chain - Eine Gleichgewichtsanalyse}}}, year = {{2017}}, } @misc{5950, author = {{Gunning, Justine}}, publisher = {{Universität Paderborn}}, title = {{{Crowdfunding Plattformen als Vermittler auf zweiseitigen Märkten - Eine mikroökonomische Analyse}}}, year = {{2017}}, } @misc{86, author = {{Niggemeyer, Laura}}, publisher = {{Universität Paderborn}}, title = {{{Kartellabsprachen und vertikale Preisbindungen - Eine wettbewerbspolitische Analyse am Bespiel der Lebensmittelindustrie in Deutschland}}}, year = {{2017}}, } @misc{5084, author = {{Streck, Thomas}}, publisher = {{Universität Paderborn}}, title = {{{How to adequately relocate asylum applicants within the European Union - An attempt to apply matching theory in the current migration crisis}}}, year = {{2017}}, } @misc{51, author = {{Winkelhake, Nikolai}}, publisher = {{Universität Paderborn}}, title = {{{Tying und Bundling in digitalen Märkten - eine wettbewerbspolitische Analyse}}}, year = {{2017}}, } @inproceedings{66, abstract = {{In budget games, players compete over resources with finite budgets. For every resource, a player has a specific demand and as a strategy, he chooses a subset of resources. If the total demand on a resource does not exceed its budget, the utility of each player who chose that resource equals his demand. Otherwise, the budget is shared proportionally. In the general case, pure Nash equilibria (NE) do not exist for such games. In this paper, we consider the natural classes of singleton and matroid budget games with additional constraints and show that for each, pure NE can be guaranteed. In addition, we introduce a lexicographical potential function to prove that every matroid budget game has an approximate pure NE which depends on the largest ratio between the different demands of each individual player.}}, author = {{Drees, Maximilian and Feldotto, Matthias and Riechers, Sören and Skopalik, Alexander}}, booktitle = {{Proceedings of the 23rd International Computing and Combinatorics Conference (COCOON)}}, pages = {{175----187}}, title = {{{Pure Nash Equilibria in Restricted Budget Games}}}, doi = {{10.1007/978-3-319-62389-4_15}}, year = {{2017}}, } @article{1054, abstract = {{We explore how competition between physicians affects medical service provision. Previous research has shown that, without competition, physicians deviate from patient‐optimal treatment under payment systems like capitation and fee‐for‐service. Although competition might reduce these distortions, physicians usually interact with each other repeatedly over time and only a fraction of patients switches providers at all. Both patterns might prevent competition to work in the desired direction. To analyze the behavioral effects of competition, we develop a theoretical benchmark that is then tested in a controlled laboratory experiment. Experimental conditions vary physician payment and patient characteristics. Real patients benefit from provision decisions made in the experiment. Our results reveal that, in line with the theoretical prediction, introducing competition can reduce overprovision and underprovision, respectively. The observed effects depend on patient characteristics and the payment system, though. Tacit collusion is observed and particularly pronounced with fee‐for‐service payment, but it appears to be less frequent than in related experimental research on price competition. }}, author = {{Brosig-Koch, Janet and Hehenkamp, Burkhard and Kokot, Johanna}}, journal = {{Health Economics}}, number = {{53}}, pages = {{6--20}}, publisher = {{Wiley Online Library}}, title = {{{The effects of competition on medical service provision}}}, doi = {{10.1002/hec.3583}}, volume = {{26}}, year = {{2017}}, } @techreport{1055, author = {{Hehenkamp, Burkhard and Kaarboe, Oddvar}}, publisher = {{Universität Paderborn}}, title = {{{Location Choice and Quality Competition in Mixed Hospital Markets}}}, year = {{2017}}, } @techreport{1056, author = {{Gu, Yiguan and Hehenkamp, Burkhard and Leininger, Wolfgang}}, publisher = {{Universität Paderborn}}, title = {{{Evolutionary Equilibrium in Stochastic Contests - Entry, Effort, and Overdissipation}}}, year = {{2017}}, } @techreport{1057, author = {{Sürücü, Oktay and Mir Djawadi, Behnud and Brangewitz, Sonja}}, publisher = {{Universität Paderborn}}, title = {{{Asymmetric Dominance Effect with Multiple Decoys for Low- and High-Variance Lotteries}}}, year = {{2017}}, } @misc{1069, author = {{Petersen, Henning Cornelius}}, publisher = {{Universität Paderborn}}, title = {{{Zu den Wechselwirkungen von Wettbewerb und Innovation - Eine ökonomische Analyse}}}, year = {{2017}}, } @misc{1070, author = {{Turan, Alparslan}}, publisher = {{Universität Paderborn}}, title = {{{Zu den Anreizwirkungen der Kronzeugenregelung - Eine spieltheoretische Analyse}}}, year = {{2017}}, } @misc{1071, author = {{Iding, Jerome}}, publisher = {{Universität Paderborn}}, title = {{{Zu den Anreiz- und Wohlfahrtswirkungen der Kronzeugenregelung - Das Fallbeispiel des LKW-Kartells (1997-2011)}}}, year = {{2017}}, } @misc{1072, author = {{Lütkevedder, Dennis}}, publisher = {{Universität Paderborn}}, title = {{{Vertikale Wettbewerbsbeschränkung auf Hotelreservierungsportalen - eine ökonomische Analyse anhand der Bestpreisklausel von Booking}}}, year = {{2017}}, }