The Consumer Price Index (CPI) is a tool used to measure inflation—specifically, the average change in the prices of goods and services that people usually buy. In simple terms, it helps us see how much the cost of living is rising or falling over time.The CPI works like this: Government agencies, such as the Philippine Statistics Authority (PSA), track the prices of a “basket” of goods and services that an average Filipino household consumes. This basket includes items like rice, vegetables, fuel, electricity, transportation fares, tuition, rent, and medicine. Each item in the basket is given a “weight” depending on how important it is to a typical family. For example, rice has a bigger weight because most Filipino households eat rice every day.The prices of these goods are collected every month from different regions. The PSA then compares the current total cost of the basket to the cost in a “base year.” If the basket costs more than before, CPI goes up—this means there is inflation. If the basket costs less, it indicates deflation.CPI is very important for students and families because it shows how much more expensive life is getting. If CPI is rising quickly, it means that people’s money is not buying as much as it used to. A 5% rise in CPI means that what cost ₱1,000 last year now costs ₱1,050. This helps employers, government, and businesses adjust wages, prices, and policies.For example, if CPI shows that food prices have gone up a lot in Mindanao due to typhoons, the government may release subsidies or aid. If CPI is high nationwide, the Bangko Sentral ng Pilipinas may increase interest rates.CPI is also used to adjust salaries and pensions through something called the Cost of Living Allowance (COLA). So when inflation goes up, public workers or retirees can receive extra pay to help them cope.In short, CPI is like a mirror—it reflects how much harder or easier it is to survive financially. Understanding CPI helps students, families, and the government make smarter decisions.