The goal of the various price indices is to measure the price changes for an array of products on a month-by-month basis, thereby to gauge the level of inflation. Two well known price indices are the Producer Price Index (PPI) and the Consumer Price Index (CPI). The PPI measures the month-by-month change in prices that producers receive for their products, retrieved using surveys from various sectors including manufacturing, agriculture, mining, and utilities. The CPI is a consumer-level analysis of the month-by-month cost to buy a set basket of goods and services. It is considered one of the most effective indicators revealing the current state of inflation in an economy.