Postal Service

In response to a congressional request, GAO reviewed the U.S. Postal Service's (USPS) 1985 mail delivery cost study to determine whether the use of neighborhood delivery and collection box units, or cluster boxes, reduced mail delivery costs.

GAO noted that, because of statistical methodological and data entry flaws that made the delivery cost estimates invalid, USPS revised the study. Using the revised estimates, GAO found that, in 1985: (1) 1.9 million, or 4 percent, of the 53 million daily city mail deliveries were to cluster boxes; (2) 94 percent of the cluster boxes were located in apartments, townhouses, and detached homes; (3) the annual cost of cluster box delivery for residential customers living in detached homes was about $10 less per customer than the cost of providing curbside mailbox delivery and produced cost savings nationwide of about $4.5 million; (4) the annual cost per cluster box delivery for customers living in townhouses was about $11 less than delivery to a mailbox located at a door and produced cost savings of about $6.9 million; and (5) the annual cost per cluster box delivery to low-rise apartment customers was the same as delivery to interior lobby boxes.