@article{3936, author = {{Gutt, Dominik and Herrmann, Philipp and Rahman, Mohammad}}, journal = {{Information Systems Research}}, number = {{3}}, pages = {{980--994}}, title = {{{Crowd-Driven Competitive Intelligence: Understanding the Relationship between Local Market Competition and Online Rating Distributions}}}, volume = {{30}}, year = {{2019}}, } @inproceedings{5471, abstract = {{We characterise the set of dominant strategy incentive compatible (DSIC), strongly budget balanced (SBB), and ex-post individually rational (IR) mechanisms for the multi-unit bilateral trade setting. In such a setting there is a single buyer and a single seller who holds a finite number k of identical items. The mechanism has to decide how many units of the item are transferred from the seller to the buyer and how much money is transferred from the buyer to the seller. We consider two classes of valuation functions for the buyer and seller: Valuations that are increasing in the number of units in possession, and the more specific class of valuations that are increasing and submodular. Furthermore, we present some approximation results about the performance of certain such mechanisms, in terms of social welfare: For increasing submodular valuation functions, we show the existence of a deterministic 2-approximation mechanism and a randomised e/(1-e) approximation mechanism, matching the best known bounds for the single-item setting.}}, author = {{Lazos, Philip and Goldberg, Paul and Skopalik, Alexander and Gerstgrasser, Matthias and de Keijzer, Bart}}, booktitle = {{Proceedings of the Thirty-Third AAAI Conference on Artificial Intelligence (AAAI)}}, location = {{Honolulu, Hawaii, USA}}, title = {{{ Multi-unit Bilateral Trade}}}, doi = {{10.1609/aaai.v33i01.33011973}}, year = {{2019}}, } @inproceedings{6856, author = {{Müller, Michelle and Gutt, Dominik}}, booktitle = {{Wirtschaftsinformatik Proceedings 2019}}, location = {{Siegen, Germany}}, title = {{{Heart over Heels? An Empirical Analysis of the Relationship between Emotions and Review Helpfulness for Experience and Credence Goods}}}, year = {{2019}}, } @inproceedings{6857, author = {{Poniatowski, Martin and Neumann, Jürgen and Görzen, Thomas and Kundisch, Dennis}}, booktitle = {{Wirtschaftsinformatik Proceedings 2019}}, location = {{Siegen, Germany}}, title = {{{A Semi-Automated Approach for Generating Online Review Templates, }}}, year = {{2019}}, } @inproceedings{10586, abstract = {{We consider the problem of transforming a given graph G_s into a desired graph G_t by applying a minimum number of primitives from a particular set of local graph transformation primitives. These primitives are local in the sense that each node can apply them based on local knowledge and by affecting only its 1-neighborhood. Although the specific set of primitives we consider makes it possible to transform any (weakly) connected graph into any other (weakly) connected graph consisting of the same nodes, they cannot disconnect the graph or introduce new nodes into the graph, making them ideal in the context of supervised overlay network transformations. We prove that computing a minimum sequence of primitive applications (even centralized) for arbitrary G_s and G_t is NP-hard, which we conjecture to hold for any set of local graph transformation primitives satisfying the aforementioned properties. On the other hand, we show that this problem admits a polynomial time algorithm with a constant approximation ratio.}}, author = {{Scheideler, Christian and Setzer, Alexander}}, booktitle = {{Proceedings of the 46th International Colloquium on Automata, Languages, and Programming}}, keywords = {{Graphs transformations, NP-hardness, approximation algorithms}}, location = {{Patras, Greece}}, pages = {{150:1----150:14}}, publisher = {{Dagstuhl Publishing}}, title = {{{On the Complexity of Local Graph Transformations}}}, doi = {{10.4230/LIPICS.ICALP.2019.150}}, volume = {{132}}, year = {{2019}}, } @inproceedings{12870, author = {{Feldkord, Björn and Knollmann, Till and Malatyali, Manuel and Meyer auf der Heide, Friedhelm}}, booktitle = {{Proceedings of the 17th Workshop on Approximation and Online Algorithms (WAOA)}}, pages = {{120 -- 137}}, publisher = {{Springer}}, title = {{{Managing Multiple Mobile Resources}}}, doi = {{10.1007/978-3-030-39479-0_9}}, year = {{2019}}, } @inproceedings{15627, author = {{Augustine, John and Hinnenthal, Kristian and Kuhn, Fabian and Scheideler, Christian and Schneider, Philipp}}, booktitle = {{Proceedings of the Fourteenth Annual ACM-SIAM Symposium on Discrete Algorithms}}, isbn = {{9781611975994}}, pages = {{1280--1299}}, title = {{{Shortest Paths in a Hybrid Network Model}}}, doi = {{10.1137/1.9781611975994.78}}, year = {{2019}}, } @proceedings{14829, editor = {{Scheideler, Christian and Berenbrink, Petra}}, isbn = {{978-1-4503-6184-2}}, publisher = {{ACM}}, title = {{{The 31st ACM Symposium on Parallelism in Algorithms and Architectures, SPAA 2019, Phoenix, AZ, USA, June 22-24, 2019}}}, doi = {{10.1145/3323165}}, year = {{2019}}, } @techreport{15202, abstract = {{In this paper, we analyze the two-dimensional Nash bargaining solution (NBS) deploying a standard labor market negotiations model (see McDonald and Solow, 1981; Creedy and McDonald, 1991). We show that the two-dimensional bargaining problem can be decomposed into two one-dimensional problems such that the (Cartesian) product of the solutions of these problems replicates the solution of the two-dimensional problem, if the NBS is applied. However, this decomposition fails for any solution concept that does not satisfy the axiom of Independence of Irrelevant Alternatives (IIA axiom). Our decomposition result has significant implications for actual negotiations, as it allows for the decomposition of a multi-issue bargaining problem into a set of simpler problems, in particular a set of single-issue bargaining problems. In this way, the decomposition may help facilitate negotiations in labor markets and also in other environments.}}, author = {{Haake, Claus-Jochen and Upmann, Thorsten and Duman, Papatya}}, keywords = {{Labor market negotiations, Efficient bargains, Nash bargaining solution, Sequential bargaining, Restricted bargaining games}}, publisher = {{CIE Working Paper Series, Paderborn University}}, title = {{{The Decomposability of the Nash Bargaining Solution in Labor Markets}}}, volume = {{128}}, year = {{2019}}, } @techreport{15204, abstract = {{We criticize some conceptual weaknesses in the recent literature on coalitional TUgames and propose, based on our critics, a new definition of dual TU-games that coincides with the one in the literature on the class of super-additive games. We justify our new definition in four alternative ways: 1. Via an adequate definition of ecient payo vectors. 2. Via a modification of the Bondareva-Shapley duality. 3. Via an explicit consideration of \coalition building". 4. Via associating general TU-games to coalition-production economies. Rather than imputations, we base our analysis on a modification of aspirations.}}, author = {{Aslan, Fatma and Duman, Papatya and Trockel, Walter}}, keywords = {{TU-games, duality, core, c-Core, cohesive games, complete game efficiency}}, publisher = {{CIE Working Paper Series, Paderborn University}}, title = {{{Duality for General TU-games Redefined}}}, volume = {{121}}, year = {{2019}}, } @article{13873, author = {{Feldkord, Björn and Meyer auf der Heide, Friedhelm}}, journal = {{ACM Transactions on Parallel Computing (TOPC)}}, number = {{3}}, title = {{{The Mobile Server Problem}}}, doi = {{10.1145/3364204}}, volume = {{6}}, year = {{2019}}, } @inproceedings{13942, author = {{Markarian, Christine and Meyer auf der Heide, Friedhelm}}, booktitle = {{Proceedings of the 8th International Conference on Operations Research and Enterprise Systems}}, pages = {{315--321}}, publisher = {{SciTePress}}, title = {{{Online Algorithms for Leasing Vertex Cover and Leasing Non-metric Facility Location}}}, doi = {{10.5220/0007369503150321}}, year = {{2019}}, } @article{13946, author = {{Abu-Khzam, Faisal N. and Li, Shouwei and Markarian, Christine and Meyer auf der Heide, Friedhelm and Podlipyan, Pavel}}, journal = {{Theoretical Computer Science}}, pages = {{2--12}}, title = {{{Efficient parallel algorithms for parameterized problems}}}, doi = {{10.1016/j.tcs.2018.11.006}}, volume = {{786}}, year = {{2019}}, } @inproceedings{14539, author = {{Castenow, Jannik and Kolb, Christina and Scheideler, Christian}}, booktitle = {{Proceedings of the 26th International Colloquium on Structural Information and Communication Complexity (SIROCCO)}}, location = {{L'Aquila, Italy}}, pages = {{345--348}}, title = {{{A Bounding Box Overlay for Competitive Routing in Hybrid Communication Networks}}}, doi = {{10.1007/978-3-030-24922-9\_26}}, year = {{2019}}, } @article{13148, abstract = {{This paper examines the evolutionary stability of behaviour in contests where players’ participation can be stochastic. We find, for exogenously given participation probabilities, players exert more effort under the concept of a finite-population evolutionarily stable strategy (FPESS) than under Nash equilibrium (NE). We show that there is ex-ante overdissipation under FPESS for sufficiently large participation probabilities, if, and only if, the impact function is convex. With costly endogenous entry, players enter the contest with a higher probability and exert more effort under FPESS than under NE. Importantly, under endogenous entry, overdissipation can occur for all (Tullock) contest success functions, in particular those with concave impact functions.}}, author = {{Gu, Yiquan and Hehenkamp, Burkhard and Leininger, Wolfgang}}, issn = {{0167-2681}}, journal = {{Journal of Economic Behavior & Organization}}, pages = {{469--485}}, title = {{{Evolutionary equilibrium in contests with stochastic participation: Entry, effort and overdissipation}}}, doi = {{10.1016/j.jebo.2019.06.011}}, year = {{2019}}, } @inproceedings{13182, abstract = {{We consider congestion control in peer-to-peer distributed systems. The problem can be reduced to the following scenario: Consider a set $V$ of $n$ peers (called \emph{clients} in this paper) that want to send messages to a fixed common peer (called \emph{server} in this paper). We assume that each client $v \in V$ sends a message with probability $p(v) \in [0,1)$ and the server has a capacity of $\sigma \in \mathbb{N}$, i.e., it can recieve at most $\sigma$ messages per round and excess messages are dropped. The server can modify these probabilities when clients send messages. Ideally, we wish to converge to a state with $\sum p(v) = \sigma$ and $p(v) = p(w)$ for all $v,w \in V$. We propose a \emph{loosely} self-stabilizing protocol with a slightly relaxed legitimate state. Our protocol lets the system converge from \emph{any} initial state to a state where $\sum p(v) \in \left[\sigma \pm \epsilon\right]$ and $|p(v)-p(w)| \in O(\frac{1}{n})$. This property is then maintained for $\Omega(n^{\mathfrak{c}})$ rounds in expectation. In particular, the initial client probabilities and server variables are not necessarily well-defined, i.e., they may have arbitrary values. Our protocol uses only $O(W + \log n)$ bits of memory where $W$ is length of node identifiers, making it very lightweight. Finally we state a lower bound on the convergence time an see that our protocol performs asymptotically optimal (up to some polylogarithmic factor). }}, author = {{Feldmann, Michael and Götte, Thorsten and Scheideler, Christian}}, booktitle = {{Proceedings of the 21st International Symposium on Stabilization, Safety, and Security of Distributed Systems (SSS)}}, pages = {{149--164}}, publisher = {{Springer, Cham}}, title = {{{A Loosely Self-stabilizing Protocol for Randomized Congestion Control with Logarithmic Memory}}}, doi = {{https://doi.org/10.1007/978-3-030-34992-9_13}}, year = {{2019}}, } @misc{10277, author = {{Althaus, Steffen}}, title = {{{Optimizing Sales Channel Performance with Digital Experiments in the Crafting Industry}}}, year = {{2019}}, } @inproceedings{10281, abstract = {{Competing firms tend to select similar locations for their stores. This phenomenon, called the principle of minimum differentiation, was captured by Hotelling with a landmark model of spatial competition but is still the object of an ongoing scientific debate. Although consistently observed in practice, many more realistic variants of Hotelling's model fail to support minimum differentiation or do not have pure equilibria at all. In particular, it was recently proven for a generalized model which incorporates negative network externalities and which contains Hotelling's model and classical selfish load balancing as special cases, that the unique equilibria do not adhere to minimum differentiation. Furthermore, it was shown that for a significant parameter range pure equilibria do not exist. We derive a sharp contrast to these previous results by investigating Hotelling's model with negative network externalities from an entirely new angle: approximate pure subgame perfect equilibria. This approach allows us to prove analytically and via agent-based simulations that approximate equilibria having good approximation guarantees and that adhere to minimum differentiation exist for the full parameter range of the model. Moreover, we show that the obtained approximate equilibria have high social welfare.}}, author = {{Feldotto, Matthias and Lenzner, Pascal and Molitor, Louise and Skopalik, Alexander}}, booktitle = {{Proceedings of the 18th International Conference on Autonomous Agents and MultiAgent Systems}}, location = {{Montreal QC, Canada}}, pages = {{1949----1951}}, publisher = {{International Foundation for Autonomous Agents and Multiagent Systems}}, title = {{{ From Hotelling to Load Balancing: Approximation and the Principle of Minimum Differentiation}}}, year = {{2019}}, } @phdthesis{10290, author = {{Gutt, Dominik}}, title = {{{Essays on Drivers and Economic Outcomes of Online-Reviews}}}, doi = {{10.17619/UNIPB/1-688}}, year = {{2019}}, } @techreport{10332, abstract = {{We analyze the incentives for retail bundling and the welfare effects of retail bundling in a decentralized distribution channel with two retailers and two monopolistic manufacturers. One manufacturer exclusively sells his good to one retailer, whereas the other manufacturer sells his good to both retailers. Thus, one retailer is a monopolist for one product but competes with the other retailer in the second product market. The two-product retailer has the option to bundle his goods or to sell them separately. We find that bundling aggravates the double marginalization problem for the bundling retailer. Nevertheless, when the retailers compete in prices, bundling can be more profitable than separate selling for the retailer as bundling softens the retail competition. The ultimate outcome depends on the manufacturers’ marginal costs. Given retail quantity competition, however, bundling is in no case the retailer’s best strategy. Furthermore, we show that profitable bundling reduces consumer and producer surplus in the equilibrium.}}, author = {{Heinzel, Joachim Maria Josef}}, keywords = {{retail bundling, leverage theory, double marginalization}}, publisher = {{CIE Working Paper Series}}, title = {{{Bundling in a Distribution Channel with Retail Competition}}}, year = {{2019}}, }