Matter, UlrichUlrichMatterHodler, RolandRolandHodler2025-12-182025-12-182025-12-0110.1257/aeri.20240115https://arbor.bfh.ch/handle/arbor/46113Hier die relevanten Paragraphen aus dem Publicationi Agreement mit der American Economic Association: The American Economic Association (hereinafter “Association”) is pleased to have the opportunity to publish Author’s manuscript and related appendices (identified by title above) (the “Manuscript”) in the American Economic Review: Insights. Association agrees to publish the Manuscript provided that the terms and conditions of this publication agreement (“Agreement”) as set forth below are met: 1. Copyright Assignment. The above-identified author, or his or her employer (“Employer”) if Manuscript is a work-for-hire for the benefit of Employer (“Assignor”), hereby assigns all right, title, and interest in and to the Manuscript, including but not limited to the worldwide copyright(s) therein, and any and all renewals and extensions thereof, and any and all other rights that Assignor now has or to which Assignor may become entitled under existing or subsequently enacted federal, state, or foreign laws. The foregoing notwithstanding, Association hereby acknowledges that for purposes of this Section 1, any data, software, and related software documentation that accompany the Manuscript (“Data and Code”) are excluded from this copyright assignment. Association claims no rights to the Data and Code other than as expressly set forth in this Agreement. 2. Other Required Documentation. Assignor further agrees to execute and deliver all other agreements or documentation reasonably required by Association. 3. Reprint Rights. a. Assignor Reprint Rights. Association hereby grants to Assignor the right to republication of the Manuscript. Assignor may republish the Manuscript as set forth above in any form, including digital repositories in universities and other institutions; provided, however, that Assignor shall include or cause to be included a proper copyright notice (“Copyright Notice”) on any republications. Copyright Notice shall be as follows: Copyright American Economic Association; reproduced with permission. b. Third Party Reprint Rights. Assignor may specify the degree of access to which Association grants others the right to reproduce the Manuscript. Check one: x Implicit consent. Grants anyone permission to reprint in all places in all forms provided that the Copyright Notice is included and Association is notified that the work is being reprinted.We study the impact of web search personalization on ideological segregation in search results. We deploy 150 synthetic internet users with randomized partisan browsing preferences across 25 US cities. These users are active during the US 2020 election and its aftermath. Daily experiments in which the users enter identical election-related queries provide strong evidence for ideological segregation in search results across locations with different partisan leanings, but only limited evidence for ideological segregation within location across users with different partisan browsing habits. We discuss the important role of the national and local (online) media landscape for understanding these results.enarticle