{"paper":{"title":"Strategy-proof Market Segmentation against Price Discrimination","license":"http://creativecommons.org/licenses/by/4.0/","headline":"In every strategy-proof segmentation, a monopolist's profit equals the uniform monopoly level while consumer surplus ranges from that level up to the buyer-optimal outcome.","cross_cats":[],"primary_cat":"econ.TH","authors_text":"Sanxi Li, Yang Yu, Yi Liu, Zhonghong Kuang","submitted_at":"2026-03-21T02:51:36Z","abstract_excerpt":"Data regulations increasingly enable consumers to switch among market segments, making segmentation an endogenous outcome of strategic interaction. We study a model in which consumers choose segments before a monopolist sets segment-specific prices, and define a segmentation as strategy-proof when no consumer with positive measure can profitably deviate. Our main result provides a complete welfare characterization: in every strategy-proof segmentation, producer surplus is pinned at the uniform monopoly profit, consumer surplus ranges from the uniform monopoly level to the buyer-optimal level, "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"in every strategy-proof segmentation, producer surplus is pinned at the uniform monopoly profit, consumer surplus ranges from the uniform monopoly level to the buyer-optimal level, and every consumer is weakly better off","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"Consumers choose segments before the monopolist observes them and sets prices, with strategy-proofness defined as no consumer with positive measure can profitably deviate","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"Strategy-proof segmentations pin producer surplus at the uniform monopoly profit while allowing consumer surplus to range continuously from the uniform monopoly level to the buyer-optimal level, with every consumer weakly better off.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"In every strategy-proof segmentation, a monopolist's profit equals the uniform monopoly level while consumer surplus ranges from that level up to the buyer-optimal outcome.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"a8d2501e79fdd940cd2f229e088623507b2d142ad5baaf069c4aaf27c365b610"},"source":{"id":"2603.20609","kind":"arxiv","version":2},"verdict":{"id":"798d2f8e-6541-458f-9f16-96b990151b60","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-15T07:50:10.439395Z","strongest_claim":"in every strategy-proof segmentation, producer surplus is pinned at the uniform monopoly profit, consumer surplus ranges from the uniform monopoly level to the buyer-optimal level, and every consumer is weakly better off","one_line_summary":"Strategy-proof segmentations pin producer surplus at the uniform monopoly profit while allowing consumer surplus to range continuously from the uniform monopoly level to the buyer-optimal level, with every consumer weakly better off.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"Consumers choose segments before the monopolist observes them and sets prices, with strategy-proofness defined as no consumer with positive measure can profitably deviate","pith_extraction_headline":"In every strategy-proof segmentation, a monopolist's profit equals the uniform monopoly level while consumer surplus ranges from that level up to the buyer-optimal outcome."},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":1,"snapshot_sha256":"acdf9602552aba5203024f152f01c5439b3d7dfab2a4826be9f4c17ffc18239e"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"}