Determinants and Effects of Buy Box Suppression on Amazon

98% of sales on Amazon.com flow through the Buy Box. However, Amazon sometimes decides not to feature any offers for a product and removes the Buy Box from the product page-a situation known as Buy Box suppression. Suppression may have severe consequences on individual sellers and might affect competition if it disciplines prices across online marketplaces. This paper studies suppression using a new, high-frequency dataset that tracks 17,754 products on Amazon.com at hourly intervals for eight weeks in 2024, along with corresponding offers from 59,301 unique competitors. We open-source both the dataset and collection code. We find that the primary reason for suppression is changes to the offers for a product on Amazon. Lower competitor prices only modestly increase the probability of suppression. Suppression has substantial impacts on sellers: products immediately fall sharply in search, ad placements completely disappear within 12 hours, and sales ranks are 12% worse after 48 hours. In contrast, we find no evidence of impacts on competitor prices in the short run. Our results highlight how Buy Box suppression acts as an important and underexplored mechanism of platform governance. CCS Concepts • Information systems → Online shopping; • Computing methodologies → Causal reasoning and diagnostics; • Applied computing → Economics.