{"type":"ScholarlyArticle","title":"Deterministic Implementation in Single-Item Auctions","authors":[{"name":"Yan Liu","slug":"yan-liu","given":"Yan","family":"Liu","affiliation":""},{"name":"Zeyu Ren","slug":"zeyu-ren","given":"Zeyu","family":"Ren","affiliation":""},{"name":"Pingzhong Tang","slug":"pingzhong-tang","given":"Pingzhong","family":"Tang","affiliation":""},{"name":"Zihe Wang","slug":"zihe-wang","given":"Zihe","family":"Wang","affiliation":""},{"name":"Yulong Zeng","slug":"yulong-zeng","given":"Yulong","family":"Zeng","affiliation":""},{"name":"Jie Zhang","slug":"jie-zhang","given":"Jie","family":"Zhang","affiliation":""}],"abstract":"Deterministic auctions are attractive in practice due to their transparency, simplicity, and ease of implementation, motivating a sharper understanding of when they can attain the same outcomes as randomized mechanisms.\r\nWe study deterministic implementation in single-item auctions under two notions of outcomes: (revenue, welfare) pairs and interim allocations.\r\nFor (revenue, welfare) pairs, we show a separation in discrete settings: there exists a pair implementable by a deterministic Bayesian incentive-compatible (BIC) auction but not by any deterministic dominant-strategy incentive-compatible (DSIC) auction.\r\nFor continuous atomless priors, we identify conditions under which deterministic DSIC auctions are equivalent to randomized BIC auctions in terms of achievable outcomes.\r\nFor interim allocations, under a strict monotonicity condition, we establish a deterministic analogue of Border's theorem for two bidders, providing a necessary and sufficient condition for deterministic DSIC implementability.\r\nUsing this characterization, we exhibit an interim allocation implementable by a randomized BIC auction but not by any deterministic DSIC auction.","doi":"10.24963/ijcai.2026/388","url":"https://ijcai.org/proceedings/2026/388","pdf":"https://ijcai.org/proceedings/2026/0388.pdf","markdown":"https://ijcai.org/proceedings/2026/388.md","bibtex":"https://ijcai.org/proceedings/2026/bibtex/388","volume":{"slug":"2026","title":"Proceedings of the Thirty-Fifth International Joint Conference on Artificial Intelligence","short_title":"IJCAI 2026","url":"https://ijcai.org/proceedings/2026/","year":2026,"location":"Bremen, Germany","dates":"15-21 August 2026","editors":"Diego Calvanese","isbn":"978-1-956792-09-6","publisher":"International Joint Conferences on Artificial Intelligence Organization","doi_prefix":"10.24963/ijcai.2026"},"section":"Game Theory and Economic Paradigms","track":"Main Track","number":388,"pages":{"first":3488,"last":3496},"keywords":["Game Theory and Economic Paradigms: Mechanism design","Game Theory and Economic Paradigms: Auctions and market-based systems"],"videos":[],"references":[],"license_note":"Copyright International Joint Conferences on Artificial Intelligence."}