The GDP Deflator is an economic measure that reflects the changes in prices of all goods and services included in a country's Gross Domestic Product (GDP). It helps to assess inflation by comparing the nominal GDP, which is measured at current prices, to the real GDP, which is adjusted for inflation. A rising GDP deflator indicates increasing prices, while a falling deflator suggests decreasing prices. To calculate the GDP deflator, the formula is: GDP Deflator = (Nominal GDP / Real GDP) × 100. This index is useful for policymakers and economists to understand the overall price level in the economy and make informed decisions regarding monetary policy and economic planning.