Because there isn't one single measure of inflation, the government and researchers use a variety of methods to get the most balanced picture of how prices fluctuate in the economy. Two of the most commonly used price indexes are the consumer price index (CPI) and the GDP deflator. The GDP deflator for this year is calculated by dividing the value of all goods and services produced in the economy this year using by theusingand multiplying by 100. However, the CPI reflects only the prices of all goods and services.