{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T22:33:03Z","timestamp":1786746783275,"version":"build-2736575974"},"posted":{"date-parts":[[2026]]},"group-title":"SSRN","reference-count":0,"publisher":"Elsevier BV","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"abstract":"<jats:p>I introduce a methodology for measuring consumer learning under supply uncertainty using highfrequency observations of secondary-market listings in the Pok\u00e9mon trading card game (TCG) grading market. Conventional studies of certified-collectible markets rely on grader-published population reports, which are released monthly and reflect the grading firm's internal database rather than the supply consumers actually observe. I propose an alternative supply signal: the count of active eBay listings at a given grade and condition, captured every six hours via the eBay Browse API. I detect supply shocks as weekly listing-count changes exceeding the card's own historical 95th percentile of \u0394 log(listings), and study price responses around these shocks via a card-andweek fixed-effects event study. The contribution is methodological. The empirical pipeline runs end to end on a single virtual private server, persists observations into a Postgres warehouse, handles regime changes (e.g., API rate-limit changes) via an explicit exclusion register, and produces reproducible monthly snapshots for paper-version pinning. I report a pilot dataset spanning 3 April through 9 May 2026 (37 calendar days), 19 active cards, 2,772 observations, and two confirmed supply-shock events. The pilot is not powered for inference; results are presented to validate the pipeline rather than to support generalisable claims about the response of prices to supply. Companion work in preparation will apply the same methodology to a 98-card universe over a 12-month horizon, at which scale event counts should support publication-grade event-study estimation. I provide the full data-collection and detection code as a public replication package.<\/jats:p>","DOI":"10.2139\/ssrn.6738162","type":"posted-content","created":{"date-parts":[[2026,5,9]],"date-time":"2026-05-09T08:00:11Z","timestamp":1778313611000},"source":"Crossref","is-referenced-by-count":0,"title":["Consumer Learning Under Supply Uncertainty: A Pilot Study of eBay Listing-Volume Shocks in the Pok\u00e9mon Card Grading Market"],"prefix":"10.2139","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-8477-9393","authenticated-orcid":true,"given":"Boon Chuan","family":"Lim","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"78","container-title":[],"original-title":[],"deposited":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T21:55:39Z","timestamp":1786744539000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.ssrn.com\/abstract=6738162"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026]]},"references-count":0,"URL":"https:\/\/doi.org\/10.2139\/ssrn.6738162","relation":{},"subject":[],"published":{"date-parts":[[2026]]},"subtype":"preprint"}}