Using U.S. Postal Service Delivery Statistics to Track Population Shifts Following a Major U.S. Disaster

Allison Plyer, Greater New Orleans Community Data Center and Tulane University
Ken Hodges, Claritas, Inc.

After natural disasters, authorities, relief agencies and businesses have an urgent need to determine the impact on population distribution. But forces powerful enough to displace large populations also disrupt the administrative data used to track population change. Hurricane Katrina provided a dramatic example of such disruption. The proposed paper would examine the impact on U.S. Postal Service monthly residential address counts for parishes in Louisiana. Commercial firms rely on these counts as an indicator of population change, but little research has been reported on their performance during normal or extraordinary times. Pre-hurricane comparisons between USPS counts and Census housing unit data would establish a baseline. Then, starting with August 2005, month by month address counts would be examined to assess their effectiveness in reflecting population displacement and recovery at the parish level. This paper will provide a rare look at the performance of a widely used resource under extreme circumstances.