How Often Must an Address List Be Re-Canvassed? Household Churn and the Cost of Stale Addresses

An address list begins rotting the day it is finished: households move, buildings appear and vanish, names change. This paper prices that decay against the cost of repairing it. With a stated household churn of 3 percent per month, the stale fraction of a list reaches 30.6 percent after a year untouched. A re-canvass costs a stated USD 1.10 per address; a delivery attempted to a stale address carries an expected penalty of USD 0.55, and each address receives two deliveries a month. Balancing canvass cost against stale-delivery penalties gives an optimal full re-canvass interval of 9 months, at which the list ends its cycle 24.0 percent stale and averages 13.9 percent stale, for a combined cost of USD 0.2747 per address per month. A churn scan shows the interval collapsing to a few months in fast-changing settlements and stretching past two years in stable ones — a single national re-canvass cycle fits neither. SIMULATED, NOT MEASURED.