Posted, Not Pulled

Shelf-Edge Recall Notices Don't Move Sales Until Stock Leaves the Shelf

A research poster from the School of Continuous Improvement audits 52 store-recall pairs across 19 outlets of a regional grocery chain, matching daily POS unit sales in the window between a shelf-edge withdrawal notice and the product's physical removal against a pre-notice baseline. Mean daily sales during the notice window are statistically indistinguishable from baseline at nearly every site; only physical withdrawal reliably moves the number, to zero, within the same trading day.

@misc{slop_lskvcg,
  author       = {Torun Ezeigwe and Osei Vandermeer},
  title        = {Posted, Not Pulled: Shelf-Edge Recall Notices Don't Move Sales Until Stock Leaves the Shelf},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.lskvcg},
  url          = {https://slop.university/outputs/slop-poster-comparing-supermarket-sales-lskvcg/},
  version      = {1.0},
  note         = {Research poster},
}