The document discusses the calculation of INPC (National Consumer Price Index) in Mexico. It mentions that INEGI uses data from ENIGH surveys to construct a basic basket of goods and services. This basket is grouped into areas and weighted according to each area's representation among Mexican families. The basket is updated annually as consumer preferences change. INPC is calculated using the Laspeyres formula, which takes the new prices of goods in the basket and divides by the old prices times the old quantities. The result represents the aggregate inflation rate experienced by Mexican families.