[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-296483-105":59,"doc-detail-296483-en":131},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":124,"head_meta":126,"extra_data":128,"updated_unix":130},105,"en","measuring-markets-for-network-goods-abstract","Measuring Markets for Network Goods - Abstract","","Market definition is challenging in settings with network effects, where substitution patterns respond to changes in network size. The study investigates these effects in social media by running an incentivized experiment on substitution under a proposed collective U.S. TikTok ban versus a scenario where only one user deactivates. Collective bans produce higher valuations of alternative apps, supported by mechanism evidence on content supply shifts and social coordination. A collective time-limit challenge further increases time on alternatives, suggesting individual-level substitution estimates can mislead market definition.",{"@graph":69,"@context":123},[70,84,106],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":40,"@type":76,"position":81},"https://docshare.wps.com/document/research-report/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/measuring-markets-for-network-goods-abstract/296483/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/measuring-markets-for-network-goods-abstract/296483.png","ImageObject",300,407,{"name":92,"@type":93},"Himbo","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-21","2026-09-18",true,{"@type":102,"interactionType":103,"userInteractionCount":105},"InteractionCounter",{"@type":104},"ViewAction",12,{"@type":107,"mainEntity":108},"FAQPage",[109,115,119],{"name":110,"@type":111,"acceptedAnswer":112},"Why is market definition difficult for network goods?","Question",{"text":113,"@type":114},"Because network effects mean consumer demand depends on network size, so substitution responses change when the network changes. This makes standard substitution estimates unreliable for predicting market-wide responses.","Answer",{"name":116,"@type":111,"acceptedAnswer":117},"How does the study compare collective versus individual TikTok deactivation?",{"text":118,"@type":114},"It runs an incentivized experiment where all users leave under a proposed collective TikTok ban and compares it with a case where only a single user deactivates. The collective ban yields higher valuations for alternative social apps.",{"name":120,"@type":111,"acceptedAnswer":121},"What mechanisms explain the difference between collective bans and individual deactivation?",{"text":122,"@type":114},"The paper provides mechanism evidence that anticipated content-supply shifts and social coordination partly explain the wedge. The relative importance of these channels varies across platforms.","https://schema.org",{"og:url":83,"og:type":125,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":127,"canonical":83},"index,follow",{"doc_id":129,"site_id":62},296483,1789733033,{"code":4,"msg":5,"data":132},{"doc_id":129,"user_id":133,"nickname":92,"user_avatar":134,"doc_module":4,"category_id":39,"category_name":40,"doc_title":65,"doc_description":67,"doc_content":135,"file_id":136,"file_url":137,"file_type":138,"file_size":139,"view_count":105,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":140,"language":141,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":142,"faqs":143,"seo_title":144,"seo_description":67,"update_tm":130,"read_time":145,"preview_page_count":4},687197100911,"https://ap-avatar.wpscdn.com/avatar/a000239b6f1da00475?x-image-process=image/resize,m_fixed,w_180,h_180&k=1785132997149421697","Measuring Markets for Network Goods ∗  \nLeonardo Bursztyn† Matthew Gentzkow‡ Rafael Jim´enez-Dur´an§ Aaron Leonard¶ Filip Milojevi´c ‖ Christopher Roth∗∗  \nApril 25, 2026  \nAbstract  \nMarket definition is challenging in settings with network effects, where substitution patterns depend on changes in network size. We study these effects in the context of social media. We conduct an incentivized experiment comparing substitution in response to a proposed U.S. TikTok ban, in which all users simultaneously leave the app, with substitution when only a single user deactivates. We find substantially higher valuations of alternative social apps under a collective TikTok ban than under an individual TikTok deactivation. Mechanism evidence shows that both anticipated content-supply shifts and social coordination partly explain the wedge, with the relative importance of each channel varying across platforms. We then show that a collective time limit challenge, where peers jointly reduce TikTok and Instagram use, leads to more time spent on alternative social apps than has been observed in prior individual deactivation experiments. Together, our results suggest that individual-level substitution estimates can be an unreliable guide to market definition for network goods.  \nKeywords: Market Definition, Network Goods, Coordination, Substitution, Social Media.  \nJEL Classification: D85, L00, L40  \n∗We are grateful to Guy Aridor and Julian Wright for useful comments. Utkarsh Dandanayak, Jan Fasnacht, Ari Jacob, Milena Jessen, Max M¨uller, Arthur Welch, and especially Luca Moreno-Louzada provided excellent research assistance. The research described in this article was approved by the University of Chicago Social and Behavioral Sciences Institutional Review Board. We acknowledge NOMO Technologies, Inc. for sharing data used in this study. Roth acknowledges funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy EXC 2126/2-390838866 . This work was partially supported by the RCN through its CoE Scheme, FAIR project No 262675 . Disclosures: Leonardo Bursztyn is the founder and CEO of NOMO and holds equity. Matthew Gentzkow is a scientific advisor for NOMO and holds equity.  \n†University of Chicago and NBER, [bursztyn@uchicago.edu](bursztyn@uchicago.edu)  \n‡Stanford University and NBER, [gentzkow@stanford.edu](gentzkow@stanford.edu)  \n§ Bocconi University, IGIER, CESifo, CEPR, and Stigler Center, rafael .jimenez@unibocconi .it ¶ University of Chicago, [aaronleonard@uchicago.edu](aaronleonard@uchicago.edu)  \n‖University of Chicago, [milojevic@uchicago.edu](milojevic@uchicago.edu)  \n∗∗ University of Cologne, CESifo, and CEPR, [roth@wiso.uni-koeln.de](roth@wiso.uni-koeln.de)  \n1 Introduction  \nMarket definition is central to antitrust analysis, guiding assessments of market power, competition, and consumer harm. Consider the recent U.S. antitrust case against Meta, which hinged critically on defining the “relevant market” in which Meta’s platforms compete. The Federal Trade Commission (FTC) argued that the market comprised only “personal social networking services”—platforms like Facebook and Instagram that connect users with friends and family—excluding entertainment-based apps such as YouTube and TikTok. Meta countered that the market should include all platforms competing for user attention. In November 2025, the court ruled in favor of Meta, finding that TikTok and YouTube are reasonable substitutes based on evidence of consumer switching across platforms.1  \nA first step in market definition assessments is determining which products are substitutes. Empirical estimates of substitution patterns often capture how the unavailability of a given product affects consumer demand for alternative products—for example, through deactivation studies in the case of digital products (Allcott et al. , 2020; Aridor, 2025) . Such evidence primarily relies on individual-level interventions, which eval","cbCaidF4pjKWlbFk","https://ap.wps.com/l/cbCaidF4pjKWlbFk","pdf",968204,59,"English","# Abstract\n# Introduction\n## Market definition and substitution\n## Network effects and identification\n# Design\n## Experimental setup\n## Participants and recruitment","[{\"question\":\"Why is market definition difficult for network goods?\",\"answer\":\"Because network effects mean consumer demand depends on network size, so substitution responses change when the network changes. This makes standard substitution estimates unreliable for predicting market-wide responses.\"},{\"question\":\"How does the study compare collective versus individual TikTok deactivation?\",\"answer\":\"It runs an incentivized experiment where all users leave under a proposed collective TikTok ban and compares it with a case where only a single user deactivates. The collective ban yields higher valuations for alternative social apps.\"},{\"question\":\"What mechanisms explain the difference between collective bans and individual deactivation?\",\"answer\":\"The paper provides mechanism evidence that anticipated content-supply shifts and social coordination partly explain the wedge. The relative importance of these channels varies across platforms.\"}]","Measuring Markets for Network Goods - Abstract | PDF",149]