@misc{295, author = {{Goronczewski, Patricia}}, publisher = {{Universität Paderborn}}, title = {{{Fair Trade - An economic investigation of benefits and drawbacks}}}, year = {{2015}}, } @misc{298, author = {{Plonka, Dennis}}, publisher = {{Universität Paderborn}}, title = {{{Entwicklung von Ablösesummen und Gehälter in der Fußball-Bundesliga - Salary Caps als mögliches Modell der Chancengleichheit}}}, year = {{2015}}, } @misc{306, author = {{Kunisch, Christina}}, publisher = {{Universität Paderborn}}, title = {{{Diffusion of Innovations in Social Networks}}}, year = {{2015}}, } @misc{309, author = {{Topal, Barlas}}, publisher = {{Universität Paderborn}}, title = {{{Die Einführung der EU-Merger Guidelines - Effizienz und Wohlfahrtswirkungen}}}, year = {{2015}}, } @techreport{314, abstract = {{On an intermediate goods market we allow for vertical and horizontal product differentiation and analyze the influence of simultaneous competition for resources and customers on the market outcome. Asymmetries between intermediaries cannot arise just from distinct product qualities, but also from different production technologies. The intermediaries face either price or quantity competition on the output market and a monopolistic input supplier on the input market. We find that there exist quality and productivity differences such that for quantity competition only one intermediary is willing to procure inputs from the input supplier, while for price competition both intermediaries are willing to purchase inputs. Considering product innovation for symmetric productivities we derive equilibrium conditions on the investment costs and compare price and quantity competition. It turns out that on the one hand there exist product qualities and degrees of horizontal product differentiation for complements such that asymmetric investment equilibria fail to exist. On the other hand we find that there also exist product qualities and degrees of horizontal product differentiation for substitutes such that existence can be guaranteed if the investment costs are chosen accordingly.}}, author = {{Brangewitz, Sonja and Manegold, Jochen}}, publisher = {{Universität Paderborn}}, title = {{{Competition and Product Innovation of Intermediaries in a Differentiated Duopoly}}}, year = {{2015}}, } @misc{316, author = {{Pautz, Jannis}}, publisher = {{Universität Paderborn}}, title = {{{Budget Games with priced strategies}}}, year = {{2015}}, } @inproceedings{271, abstract = {{In \emph{bandwidth allocation games} (BAGs), the strategy of a player consists of various demands on different resources. The player's utility is at most the sum of these demands, provided they are fully satisfied. Every resource has a limited capacity and if it is exceeded by the total demand, it has to be split between the players. Since these games generally do not have pure Nash equilibria, we consider approximate pure Nash equilibria, in which no player can improve her utility by more than some fixed factor $\alpha$ through unilateral strategy changes. There is a threshold $\alpha_\delta$ (where $\delta$ is a parameter that limits the demand of each player on a specific resource) such that $\alpha$-approximate pure Nash equilibria always exist for $\alpha \geq \alpha_\delta$, but not for $\alpha < \alpha_\delta$. We give both upper and lower bounds on this threshold $\alpha_\delta$ and show that the corresponding decision problem is ${\sf NP}$-hard. We also show that the $\alpha$-approximate price of anarchy for BAGs is $\alpha+1$. For a restricted version of the game, where demands of players only differ slightly from each other (e.g. symmetric games), we show that approximate Nash equilibria can be reached (and thus also be computed) in polynomial time using the best-response dynamic. Finally, we show that a broader class of utility-maximization games (which includes BAGs) converges quickly towards states whose social welfare is close to the optimum.}}, author = {{Drees, Maximilian and Feldotto, Matthias and Riechers, Sören and Skopalik, Alexander}}, booktitle = {{Proceedings of the 8th International Symposium on Algorithmic Game Theory (SAGT)}}, pages = {{178--189}}, title = {{{On Existence and Properties of Approximate Pure Nash Equilibria in Bandwidth Allocation Games}}}, doi = {{10.1007/978-3-662-48433-3_14}}, year = {{2015}}, } @misc{277, author = {{Kothe, Nils}}, publisher = {{Universität Paderborn}}, title = {{{Multilevel Netzwerk Spiele mit konstanten Entfernungen im Highspeed-Netzwerk}}}, year = {{2015}}, } @misc{234, author = {{Menne, Maria Reinhild}}, publisher = {{Universität Paderborn}}, title = {{{Verkaufsbeschränkungen auf Onlinemarktplätzen - Eine wettbewerbspolitische Analyse am Fallbeispiel der Adidas AG}}}, year = {{2015}}, } @misc{229, author = {{Schulz, Hannah}}, publisher = {{Universität Paderborn}}, title = {{{Zur Verbreitung von Informationen in sozialen Netzwerken - eine wirtschaftspolitische Analyse}}}, year = {{2015}}, } @inproceedings{232, abstract = {{We introduce weighted boolean formula games (WBFG) as a new class of succinct games. Each player has a set of boolean formulas she wants to get satisfied; the formulas involve a ground set of boolean variables each of which is controlled by some player. The payoff of a player is a weighted sum of the values of her formulas. We consider both pure equilibria and their refinement of payoff-dominant equilibria [34], where every player is no worse-off than in any other pure equilibrium. We present both structural and complexity results:We consider mutual weighted boolean formula games (MWBFG), a subclass of WBFG making a natural mutuality assumption on the formulas of players. We present a very simple exact potential for MWBFG. We establish a polynomial monomorphism from certain classes of weighted congestion games to subclasses of WBFG and MWBFG, respectively, indicating their rich structure.We present a collection of complexity results about decision (and search) problems for both pure and payoff-dominant equilibria in WBFG. The precise complexities depend crucially on five parameters: (i) the number of players; (ii) the number of variables per player; (iii) the number of formulas per player; (iv) the weights in the payoff functions (whether identical or not), and (v) the syntax of the formulas. These results imply that, unless the polynomial hierarchy collapses, decision (and search) problems for payoff-dominant equilibria are harde than for pure equilibria.}}, author = {{Monien, Burkhard and Mavronicolas, Marios and Wagner, Klaus}}, booktitle = {{the ´Festschrift´ Algorithms, Probability, Networks, and Games: Scientific Papers and Essays Dedicated to Paul G. Spirakis on the Occasion of His 60th Birthday}}, pages = {{49--86}}, title = {{{Weighted Boolean Formula Games}}}, doi = {{10.1007/978-3-319-24024-4_6}}, year = {{2015}}, } @misc{5930, author = {{Mikroökonomie, Lehrstuhl}}, publisher = {{Universität Paderborn}}, title = {{{Bilateral matching and bargaining games}}}, year = {{2015}}, } @article{491, abstract = {{In the framework of spatial competition, two or more players strategically choose a locationin order to attract consumers. It is assumed standardly that consumers with the same favorite location fully agree on the ranking of all possible locations. To investigate the necessity of this questionable and restrictive assumption, we model heterogeneity in consumers’ distance perceptions by individual edge lengths of a given graph. A profile of location choices is called a “robust equilibrium” if it is a Nash equilibrium in several games which differ only by the consumers’ perceptions of distances. For a finite number of players and any distribution of consumers, we provide a full characterization of all robust equilibria and derive structural conditions for their existence. Furthermore, we discuss whether the classical observations of minimal differentiation and inefficiency are robust phenomena. Thereby, we find strong support for an old conjecture that in equilibrium firms form local clusters.}}, author = {{Buechel, Berno and Röhl, Nils}}, journal = {{European Journal of Operational Research}}, number = {{2}}, pages = {{505--517}}, publisher = {{Elsevier}}, title = {{{Robust Equilibria in Location Games}}}, doi = {{10.1016/j.ejor.2014.07.019}}, volume = {{240}}, year = {{2015}}, } @article{398, abstract = {{We consider strategic games in which each player seeks a mixed strategy to minimize her cost evaluated by a concave valuation V (mapping probability distributions to reals); such valuations are used to model risk. In contrast to games with expectation-optimizer players where mixed equilibria always exist (Nash 1950; Nash Ann. Math. 54, 286–295, 1951), a mixed equilibrium for such games, called a V-equilibrium, may fail to exist, even though pure equilibria (if any) transfer over. What is the exact impact of such valuations on the existence, structure and complexity of mixed equilibria? We address this fundamental question in the context of expectation plus variance, a particular concave valuation denoted as RA, which stands for risk-averse; so, variance enters as a measure of risk and it is used as an additive adjustment to expectation. We obtain the following results about RA-equilibria:A collection of general structural properties of RA-equilibria connecting to (i) E-equilibria and Var-equilibria, which correspond to the expectation and variance valuations E and Var, respectively, and to (ii) other weaker or incomparable properties such as Weak Equilibrium and Strong Equilibrium. Some of these structural properties imply quantitative constraints on the existence of mixed RA-equilibria.A second collection of (i) existence, (ii) equivalence and separation (with respect to E-equilibria), and (iii) characterization results for RA-equilibria in the new class of player-specific scheduling games. We provide suitable examples with a mixed RA-equilibrium that is not an E-equilibrium and vice versa.A purification technique to transform a player-specific scheduling game on two identical links into a player-specific scheduling game on two links so that all non-pure RA-equilibria are eliminated while no new pure equilibria are created; so, a particular player-specific scheduling game on two identical links with no pure equilibrium yields a player-specific scheduling game with no RA-equilibrium (whether mixed or pure). As a by-product, the first PLS-completeness result for the computation of RA-equilibria follows.}}, author = {{Monien, Burkhard and Mavronicolas, Marios}}, journal = {{Theory of Computing Systems}}, number = {{3}}, pages = {{617--654}}, publisher = {{Springer}}, title = {{{Minimizing Expectation Plus Variance}}}, doi = {{10.1007/s00224-014-9542-z}}, volume = {{57}}, year = {{2015}}, } @misc{5090, author = {{Streck, Thomas}}, publisher = {{Universität Paderborn}}, title = {{{Praktikabilität des Adjusted Winner Verfahrens bei variablem Status Quo- Punkt und exogenen Einflüssen}}}, year = {{2015}}, } @misc{5927, author = {{N, N}}, publisher = {{Universität Paderborn}}, title = {{{Simultane bilaterale Verhandlungen - Zur Zusammenstellung eines Sortiments}}}, year = {{2015}}, } @misc{5928, author = {{N, N}}, publisher = {{Universität Paderborn}}, title = {{{Cournot-Nash-Bertrand Wettbewerb im serviceorientierten Internet}}}, year = {{2015}}, } @misc{5929, author = {{N, N}}, publisher = {{Universität Paderborn}}, title = {{{Multilaterale Verhandlungen aus Produzentensicht}}}, year = {{2015}}, } @misc{5925, author = {{N, N}}, publisher = {{Universität Paderborn}}, title = {{{Produktdifferenzierung und Verhandlungsposition im duopolistischen Wettbewerb}}}, year = {{2015}}, } @misc{5923, author = {{N, N}}, publisher = {{Universität Paderborn}}, title = {{{Aggregating Online Reputation Feedback}}}, year = {{2015}}, }