Expecting the Expected? Documenting Nostalgia Effects on Baseball Card Prices.

The article investigates a pricing anomaly in the market for vintage Major League Baseball (MLB) trading cards, specifically a significant and persistent "death effect"—an average 20% increase in the sale price of Hall-of-Famer rookie cards following the player's death. Using interrupted time series models and high-frequency sales data of PSA-graded Topps rookie cards from nine MLB legends who died between 2017 and 2021, the study finds that prices spike immediately after death and remain elevated for at least 60 days. These findings challenge the efficient market hypothesis (EMH), as rational investors should have already priced in the inevitable deaths, suggesting unexploited profit opportunities possibly limited by transaction costs, storage, and moral considerations. The study also identifies heterogeneity in the death effect by player position and card type, contributing to broader literature on collectibles, consumer behavior, and market anomalies.