Integrality gap analysis for bin packing games

Walter Kern, X. Qui

Research output: Contribution to journalArticleAcademicpeer-review

5 Citations (Scopus)


A cooperative bin packing game is an $N$-person game, where the player set $N$ consists of $k$ bins of capacity 1 each and $n$ items of sizes $a_1,\dots,a_n$. The value $v(S)$ of a coalition $S$ of players is defined to be the maximum total size of items in $S$ that can be packed into the bins of $S$. We analyze the integrality gap of the corresponding 0–1 integer program of the value $v(N)$, thereby presenting an alternative proof for the non-emptiness of the 1/3-core for all bin packing games. Further, we show how to improve this bound $\epsilon\leq1/3$ (slightly) and point out that the conclusion in Matsui (2000) [9] is wrong (claiming that the bound 1/3 was tight). We conjecture that the true best possible value is $\epsilon=1/7$. The results are obtained using a new “rounding technique‿ that we develop to derive good (integral) packings from given fractional ones.
Original languageUndefined
Pages (from-to)360-363
Number of pages4
JournalOperations research letters
Issue number5
Publication statusPublished - Sep 2012


  • EWI-22494
  • Integrality gap
  • Core
  • Taxation rate
  • METIS-289774
  • IR-82139
  • Bin packing

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