5 C.F.R. § 591.209 What is a price index?
Title 5 - Administrative Personnel
(a) The price index is the COLA area price divided by the DC area price and multiplied by 100. (b) Example: COLA Area Average Price for Item A = $1.233 DC Area Average Price for Item A = $1.164 Computation: $1.233/$1.164 = 1.0592783 1.0592783 × 100 = 105.92783. (c) In the case of the final index, OPM rounds the index to two decimal places.
Title 5: Administrative Personnel
PART 591—ALLOWANCES AND DIFFERENTIALS
Subpart B—Cost-of-Living Allowance and Post Differential—Nonforeign Areas
Cost-of-Living Allowances
§ 591.209 What is a price index?
