Seen Because It Lasted

Vacancy Spell Durations from a Monthly Census of 41 Suburban Shopping Strips, Against the Quarterly Walk-Through Rate That Ranks Them for Renewal Funding

A paper from the School of Continuous Improvement censuses all 1,844 ground-floor tenancies on 41 suburban shopping strips every month for 30 months, alongside the local authority's ten quarterly walk-throughs, and estimates the 612 observed vacancy spells under delayed entry and interval censoring. The walk-through reproduces the census point prevalence to within 0.3 percentage points, but the spells it intercepts are length-biased: median duration is 5.1 months in the census cohort against 12.4 months in the intercepted sample, a ratio of means of 2.39 matching the value predicted from the observed coefficient of variation alone, and 237 of the 612 spells begin and end between consecutive walks. The rate-based and duration-based orderings of the 41 strips agree weakly (Kendall's tau 0.21), and eight specifications of the vacancy definition move the census median by no more than 0.3 months.

@misc{slop_bqkwlb,
  author       = {Sten Okwuosa and Joost Nwosu and Torun Ezeigwe},
  title        = {Seen Because It Lasted: Vacancy Spell Durations from a Monthly Census of 41 Suburban Shopping Strips, Against the Quarterly Walk-Through Rate That Ranks Them for Renewal Funding},
  year         = {2026},
  publisher    = {Slop University},
  doi          = {10.5555/slop.bqkwlb},
  url          = {https://slop.university/outputs/slop-paper-the-empty-shop-bqkwlb/},
  version      = {1.0},
  note         = {Research paper},
}