An index that measures changes in the prices received for crops and livestock. NASS currently publishes the index on a 1990-92=100 base. A ratio of the prices received index to the prices paid index on the 1990-92 base that is greater than 100% indicates that farm commodity prices have increased at a faster rate than farm input prices. When the ratio is less than 100%, farm input prices are increasing a more rapid pace than farm commodity prices. The prices received index and the prices paid index are used to calculate the parity ratio.