Indexation of contracts
（重定向自Index linking）
In statistics relating to national economies, the indexation of contracts also called "index linking" and "contract escalation" is a procedure when a contract includes a periodic adjustment to the prices paid for the contract provisions based on the level of a nominated price index. The purpose of indexation is to readjust contracts to account for inflation. In the United States, the consumer price index (CPI), producer price index (PPI), and, in the U.S., Employment Cost Index (ECI) are the most frequently used indexes.