@article{GrimmSoubeigaWeber2024, author = {Grimm, Michael and Soubeiga, Sidiki and Weber, Michael}, title = {Supporting small firms in a fragile context : comparing matching and cash grants in Burkina Faso}, series = {Journal of Development Economics (Online ISSN: 1872-6089)}, volume = {2024}, journal = {Journal of Development Economics (Online ISSN: 1872-6089)}, number = {171}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.jdeveco.2024.103344}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:739-opus4-18848}, pages = {17 Seiten}, year = {2024}, abstract = {We used a randomized controlled trial to compare matching grants earmarked for technical training and consulting services with more flexible cash grants and with a control group. The experiment was implemented in a semi-urban and rural fragile setting where subsidizing innovative activities might be particularly important. Firms were selected on the basis of a business plan competition. After two years, beneficiaries of cash grants showed higher survival rates, improved business practices, a higher degree of formalization, and more activities for innovation relative to recipients of matching grants and the control group, but we saw no effects on profits, sales, and employment. Across all outcomes, beneficiaries of cash grants performed better than beneficiaries of matching grants, for them the treatment effects are smaller and often insignificant, though implementation costs were higher. Recipients of cash grants also increased their capital stock more and were more resilient to the COVID-19 crisis.}, language = {en} } @article{FritschPuaSchnurbus2024, author = {Fritsch, Markus and Pua, Andrew Adrian and Schnurbus, Joachim}, title = {Teaching advanced topics in econometrics using introductory textbooks : the case of dynamic panel data methods}, series = {International Review of Economics Education (Online ISSN: 2352-4421)}, volume = {2024}, journal = {International Review of Economics Education (Online ISSN: 2352-4421)}, number = {47}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.iree.2024.100297}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:739-opus4-18835}, pages = {19 Seiten}, year = {2024}, abstract = {We show how to use the introductory econometrics textbook by Stock and Watson (2019) as a starting point for teaching and studying dynamic panel data methods. The materials are intended for undergraduate students taking their second econometrics course, undergraduate students in seminar-type courses, independent study courses, capstone, or thesis projects, and beginning graduate students in a research methods course. First, we distill the methodological core necessary to understand dynamic panel data methods. Second, we design an empirical and a theoretical case study to highlight the capabilities, downsides, and hazards of the method. The empirical case study is based on the cigarette demand example in Stock and Watson (2019) and illustrates that economic and methodological issues are interrelated. The theoretical case study shows how to evaluate current empirical practices from a theoretical standpoint. We designed both case studies to boost students' confidence in working with technical material and to provide instructors with more opportunities to let students develop econometric thinking and to actively communicate with applied economists. Although we focus on Stock and Watson (2019) and the statistical software R, we also show how to modify the material for use with another introductory textbook by Wooldridge (2020) and Stata, and highlight some possible further pathways for instructors and students to reuse and extend our materials.}, language = {en} } @article{GruenerPostelSchumann2024, author = {Gr{\"u}ner, Alina and Postel, Lea and Schumann, Jan}, title = {Sharing is caring? The effect of negative peer-to-peer experiences on loyalty intentions in the sharing economy}, series = {Journal of Business Research (Online ISSN: 1873-7978)}, volume = {2024}, journal = {Journal of Business Research (Online ISSN: 1873-7978)}, number = {181}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.jbusres.2024.114757}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:739-opus4-18820}, pages = {14 Seiten}, year = {2024}, abstract = {Negative experiences with other users (i.e., negative peer-to-peer [P2P] experiences), are a highly prevalent problem of sharing economy business models with potentially negative consequences for the platform. This paper investigates the effect of negative P2P experiences on users' platform loyalty intentions. Based on trust transfer theory, we test a moderated serial mediation suggesting that negative P2P experiences negatively affect platform loyalty intentions via a decrease in peer trust and a subsequent decrease in platform trust. The results of an online scenario-experiment (n = 265) and an online survey (n = 237) in the home-sharing context support this notion by showing a negative peers-to-platform trust transfer effect. In addition, we identified the type of negative experience (outcome-related vs. process-related) and prior relationship satisfaction as contingency factors. This paper draws platform providers' attention to the potential threat stemming from negative experiences between users and provide advice on how to attenuate a negative spillover-effect on the platform.}, language = {en} } @article{MuellerGronbachYaroslavtseva2024, author = {M{\"u}ller-Gronbach, Thomas and Yaroslavtseva, Larisa}, title = {On the complexity of strong approximation of stochastic differential equations with a non-Lipschitz drift coefficient}, series = {Journal of Complexity (Online ISSN: 1090-2708)}, volume = {2024}, journal = {Journal of Complexity (Online ISSN: 1090-2708)}, number = {85}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.jco.2024.101870}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:739-opus4-18819}, pages = {17 Seiten}, year = {2024}, abstract = {We survey recent developments in the field of complexity of pathwise approximation in p-th mean of the solution of a stochastic differential equation at the final time based on finitely many evaluations of the driving Brownian motion. First, we briefly review the case of equations with globally Lipschitz continuous coefficients, for which an error rate of at least 1/2 in terms of the number of evaluations of the driving Brownian motion is always guaranteed by using the equidistant Euler-Maruyama scheme. Then we illustrate that giving up the global Lipschitz continuity of the coefficients may lead to a non-polynomial decay of the error for the Euler-Maruyama scheme or even to an arbitrary slow decay of the smallest possible error that can be achieved on the basis of finitely many evaluations of the driving Brownian motion. Finally, we turn to recent positive results for equations with a drift coefficient that is not globally Lipschitz continuous. Here we focus on scalar equations with a Lipschitz continuous diffusion coefficient and a drift coefficient that satisfies piecewise smoothness assumptions or has fractional Sobolev regularity and we present corresponding complexity results.}, language = {en} } @article{NagelHeidenreichSchumann2024, author = {Nagel, Christian and Heidenreich, Sven and Schumann, Jan}, title = {Enhancing adoption of sustainable product innovations : addressing reduced performance with risk-reducing product modifications}, series = {Journal of Business Research (Online ISSN: 1873-7978)}, volume = {2024}, journal = {Journal of Business Research (Online ISSN: 1873-7978)}, number = {179}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.jbusres.2024.114684}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:739-opus4-18788}, pages = {12 Seiten}, year = {2024}, abstract = {Past studies have shown that the probability of the successful diffusion of sustainable product innovations is strikingly low. A potentially promising marketing strategy to reduce negative consumer perceptions of sustainable product innovations is risk-reducing product modifications (RPMs), which account for behavioral adjustments and performance uncertainties by employing an additional component that uses established technology. This research strives to empirically test the potential positive effects of RPMs using two studies on electric vehicles with and without range extenders as prime examples of RPM: (1) an online survey of potential adopters and (2) a postadoption survey of early adopters. The results show that RPMs increase the adoption of sustainable product innovations. Consumers' tendency to overestimate their true needs and their need for insurance against insufficient performance explain the effectiveness of RPM.}, language = {en} } @article{OttoTilk2024, author = {Otto, Alena and Tilk, Christian}, title = {Intelligent design of sensor networks for data-driven sensor maintenance at railways}, series = {Omega (Online ISSN: 1873-5274)}, volume = {2024}, journal = {Omega (Online ISSN: 1873-5274)}, number = {127}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.omega.2024.103094}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:739-opus4-18771}, pages = {13 Seiten}, year = {2024}, abstract = {With rapid advances in digitization, many critical processes in transportation, industries, and our daily life rely on sensor measurements. With time, however, the measurements may get gradually biased and their precision deteriorates, leading to an enhanced risk of major disruptions caused by false sensor measurements. All single sensor measurements are uncertain and deviate from the true value. To detect malfunctioning sensors early on, a set of recent measurements of each sensor has to be constantly cross-checked against the measurements of a given number of other sensors, i.e., sensors should form a diagnosable network. In this article, we examine the intelligent positioning of safety-relevant sensors at railways such that the installed sensors can constantly cross-check each other and the number of the required sensors is minimized. The arising sensor positioning problem (SPP) belongs to the family of the coordinated set covering problems with two binary matrices: the choice of columns in one matrix implies the selection of specific columns and rows in the other matrix. We formulate an integer program, provide some formal analysis of the SPP and design a customized large neighborhood search metaheuristic RuM, which finds close-to-optimality solutions fast. In our computational experiments, we show that if we ignore the diagnosability requirement, the installed sensors cannot sufficiently cross-check each other in most cases. However, it costs only a few (or even no) additional sensors to ensure the diagnosability of the sensor network.}, language = {en} } @article{FruehwirthProchno2024, author = {Fr{\"u}hwirth, Lorenz and Prochno, Joscha}, title = {Sanov-type large deviations and conditional limit theorems for high-dimensional Orlicz balls}, series = {Journal of Mathematical Analysis and Applications (Online ISSN: 1096-0813)}, volume = {2024}, journal = {Journal of Mathematical Analysis and Applications (Online ISSN: 1096-0813)}, number = {536,1}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.jmaa.2024.128169}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:739-opus4-18723}, pages = {25 Seiten}, year = {2024}, abstract = {In this paper, we prove a Sanov-type large deviation principle for the sequence of empirical measures of vectors chosen uniformly at random from an Orlicz ball. From this level-2 large deviation result, in a combination with Gibbs conditioning, entropy maximization and an Orlicz version of the Poincar{\´e}-Maxwell-Borel lemma, we deduce a conditional limit theorem for high-dimensional Orlicz balls. In more geometric parlance, the latter shows that if V1 and V2 are Orlicz functions, then random points in the V1-Orlicz ball, conditioned on having a small V2-Orlicz radius, look like an appropriately scaled V2-Orlicz ball. In fact, we show that the limiting distribution in our Poincar{\´e}-Maxwell-Borel lemma, and thus the geometric interpretation, undergoes a phase transition depending on the magnitude of the V2-Orlicz radius.}, language = {en} } @article{SchmidPetriElschner2024, author = {Schmid-Petri, Hannah and Elschner, Sophie G.}, title = {Transitionalists, traditionalists or pioneers? How German municipal energy companies are responding to the national energy transition}, series = {Energy Research \& Social Science (Online ISSN: 2214-6326)}, volume = {2024}, journal = {Energy Research \& Social Science (Online ISSN: 2214-6326)}, number = {109}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.erss.2024.103431}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:739-opus4-18714}, pages = {15 Seiten}, year = {2024}, abstract = {The Renewable Energy Sources Act (EEG) in Germany aims to transition the country to a sustainable energy system. This has led to a decentralization of the energy market and a shift toward community-focused energy supply systems. Municipal energy companies (MECs), deeply rooted in their communities, are crucial in facilitating this transition and promoting innovative technologies. Websites serve as important communication tools, facilitating interaction between companies and consumers. In our study, we conducted a quantitative content analysis to examine how MECs communicate issues related to the energy transition on their web pages (N = 300). In general, our results show that the energy transition was rarely mentioned on landing pages, and while companies are improving their sustainable electricity products, renewable gas and heating tariffs have received little attention. Additionally, we identified three communication types of MECs: The transitionalists (45 \%), the traditionalists (35 \%), and the pioneers (20 \%), with the latter being the most innovative that emphasizes issues related to the energy transition. Overall, it can be said that the MECs have not yet fully exploited their potential to position themselves as pioneers of the energy transition in their website communications.}, language = {en} } @article{KreuzerWalsh2024, author = {Kreuzer, Martin and Walsh, Florian}, title = {Computing the binomial part of a polynomial ideal}, series = {Journal of Symbolic Computation (Online ISSN: 1095-855X)}, volume = {2024}, journal = {Journal of Symbolic Computation (Online ISSN: 1095-855X)}, number = {124}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.jsc.2024.102298}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:739-opus4-18708}, pages = {30 Seiten}, year = {2024}, abstract = {Given an ideal I in a polynomial ring K[x1,...,xn] over a field K, we present a complete algorithm to compute the binomial part of I, i.e., the subideal Bin(I) of I generated by all monomials and binomials in I. This is achieved step-by-step. First we collect and extend several algorithms for computing exponent lattices in different kinds of fields. Then we generalize them to compute exponent lattices of units in 0-dimensional K-algebras, where we have to generalize the computation of the separable part of an algebra to non-perfect fields in characteristic p. Next we examine the computation of unit lattices in finitely generated K-algebras, as well as their associated characters and lattice ideals. This allows us to calculate Bin(I) when I is saturated with respect to the indeterminates by reducing the task to the 0-dimensional case. Finally, we treat the computation of Bin(I) for general ideals by computing their cellular decomposition and dealing with finitely many special ideals called (s,t)-binomial parts. All algorithms have been implemented in SageMath.}, language = {en} } @article{GoerigkKhosravi2024, author = {Goerigk, Marc and Khosravi, Mohammad}, title = {Benchmarking problems for robust discrete optimization}, series = {Computers \& Operations Research (Online ISSN: 1873-765X)}, volume = {2024}, journal = {Computers \& Operations Research (Online ISSN: 1873-765X)}, number = {166}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.cor.2024.106608}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:739-opus4-18752}, pages = {16 Seiten}, year = {2024}, abstract = {Robust discrete optimization is a highly active field of research where a plenitude of combinations between decision criteria, uncertainty sets and underlying nominal problems are considered. Usually, a robust problem becomes harder to solve than its nominal counterpart, even if it remains in the same complexity class. For this reason, specialized solution algorithms have been developed. To further drive the development of stronger solution algorithms and to facilitate the comparison between methods, a set of benchmark instances is necessary but so far missing. In this paper we propose a further step towards this goal by proposing several instance generation procedures for combinations of min-max, min-max regret, two-stage and recoverable robustness with interval, discrete, budgeted or ellipsoidal uncertainty sets. Besides sampling methods that go beyond the simple uniform sampling method that is the de-facto standard to produce instances, also optimization models to construct hard instances are considered. Using a selection problem for the nominal ground problem, we are able to generate instances that are several orders of magnitudes harder to solve than uniformly sampled instances when solving them with a general mixed-integer programming solver. All instances and generator codes are made available online.}, language = {en} }