@article{Schlosser2020,
  author    = {Schlosser, Rainer},
  title     = {Risk-sensitive control of Markov decision processes},
  series = {Computers \& operations research : and their applications to problems of world concern},
  volume    = {123},
  journal   = {Computers \& operations research : and their applications to problems of world concern},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0305-0548},
  doi       = {10.1016/j.cor.2020.104997},
  pages     = {14},
  year      = {2020},
  abstract  = {In many revenue management applications risk-averse decision-making is crucial. In dynamic settings, however, it is challenging to find the right balance between maximizing expected rewards and minimizing various kinds of risk. In existing approaches utility functions, chance constraints, or (conditional) value at risk considerations are used to influence the distribution of rewards in a preferred way. Nevertheless, common techniques are not flexible enough and typically numerically complex. In our model, we exploit the fact that a distribution is characterized by its mean and higher moments. We present a multi-valued dynamic programming heuristic to compute risk-sensitive feedback policies that are able to directly control the moments of future rewards. Our approach is based on recursive formulations of higher moments and does not require an extension of the state space. Finally, we propose a self-tuning algorithm, which allows to identify feedback policies that approximate predetermined (risk-sensitive) target distributions. We illustrate the effectiveness and the flexibility of our approach for different dynamic pricing scenarios. (C) 2020 Elsevier Ltd. All rights reserved.},
  language  = {en}
}
@article{Schlosser2022,
  author    = {Schlosser, Rainer},
  title     = {Heuristic mean-variance optimization in Markov decision processes using state-dependent risk aversion},
  series = {IMA journal of management mathematics / Institute of Mathematics and Its Applications},
  volume    = {33},
  journal   = {IMA journal of management mathematics / Institute of Mathematics and Its Applications},
  number    = {2},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {1471-678X},
  doi       = {10.1093/imaman/dpab009},
  pages     = {181 -- 199},
  year      = {2022},
  abstract  = {In dynamic decision problems, it is challenging to find the right balance between maximizing expected rewards and minimizing risks. In this paper, we consider NP-hard mean-variance (MV) optimization problems in Markov decision processes with a finite time horizon. We present a heuristic approach to solve MV problems, which is based on state-dependent risk aversion and efficient dynamic programming techniques. Our approach can also be applied to mean-semivariance (MSV) problems, which particularly focus on the downside risk. We demonstrate the applicability and the effectiveness of our heuristic for dynamic pricing applications. Using reproducible examples, we show that our approach outperforms existing state-of-the-art benchmark models for MV and MSV problems while also providing competitive runtimes. Further, compared to models based on constant risk levels, we find that state-dependent risk aversion allows to more effectively intervene in case sales processes deviate from their planned paths. Our concepts are domain independent, easy to implement and of low computational complexity.},
  language  = {en}
}
@article{Schlosser2020,
  author    = {Schlosser, Rainer},
  title     = {Scalable relaxation techniques to solve stochastic dynamic multi-product pricing problems with substitution effects},
  series = {Journal of revenue and pricing management},
  volume    = {20},
  journal   = {Journal of revenue and pricing management},
  number    = {1},
  publisher = {Palgrave Macmillan},
  address   = {Basingstoke},
  issn      = {1476-6930},
  doi       = {10.1057/s41272-020-00249-z},
  pages     = {54 -- 65},
  year      = {2020},
  abstract  = {In many businesses, firms are selling different types of products, which share mutual substitution effects in demand. To compute effective pricing strategies is challenging as the sales probabilities of each of a firm's products can also be affected by the prices of potential substitutes. In this paper, we analyze stochastic dynamic multi-product pricing models for the sale of perishable goods. To circumvent the limitations of time-consuming optimal solutions for highly complex models, we propose different relaxation techniques, which allow to reduce the size of critical model components, such as the state space, the action space, or the set of potential sales events. Our heuristics are able to decrease the size of those components by forming corresponding clusters and using subsets of representative elements. Using numerical examples, we verify that our heuristics make it possible to dramatically reduce the computation time while still obtaining close-to-optimal expected profits. Further, we show that our heuristics are (i) flexible, (ii) scalable, and (iii) can be arbitrarily combined in a mutually supportive way.},
  language  = {en}
}