• Media type: E-Article
  • Title: Average optimality for Markov decision processes in borel spaces: a new condition and approach
  • Contributor: Guo, Xianping; Zhu, Quanxin
  • Published: Cambridge University Press (CUP), 2006
  • Published in: Journal of Applied Probability, 43 (2006) 2, Seite 318-334
  • Language: English
  • DOI: 10.1239/jap/1152413725
  • ISSN: 0021-9002; 1475-6072
  • Origination:
  • Footnote:
  • Description: <jats:p>In this paper we study discrete-time Markov decision processes with Borel state and action spaces. The criterion is to minimize average expected costs, and the costs may have <jats:italic>neither upper nor lower</jats:italic> bounds. We first provide <jats:italic>two</jats:italic> average optimality inequalities of opposing directions and give conditions for the existence of solutions to them. Then, using the two inequalities, we ensure the existence of an average optimal (deterministic) stationary policy under additional continuity-compactness assumptions. Our conditions are slightly <jats:italic>weaker</jats:italic> than those in the previous literature. Also, some <jats:italic>new</jats:italic> sufficient conditions for the existence of an average optimal stationary policy are imposed on the <jats:italic>primitive data</jats:italic> of the model. Moreover, our approach is slightly different from the well-known ‘optimality inequality approach’ widely used in Markov decision processes. Finally, we illustrate our results in two examples.</jats:p>