Evolution and forecast of basic food basket prices in Fortaleza from january 1994 to may 2023

Abstract

This study sought to analyze the projection of the price of the basic food basket in Fortaleza between January 1994 and May 2023, in addition to verifying the hypothesis of the influence of rainfall on the predicted value of the basic food basket. Monthly rainfall data were obtained from the Ceará Foundation for Meteorology and Hydric Resources (FUNCEME). The series of prices and minimum wages were obtained from the Inter-Union Department of Statistics and Socioeconomic Studies (DIEESE). The values were indexed by the INPC of IBGE and converted into USD of May 2023. The average values, coefficients of variation and geometric growth rates of the annual minimum wage, the average annual price of basic food and rainfall were estimated. An integrated autoregressive moving average ARIMA model (2.1.1) was fitted to capture the trajectory and forecast the prices of the basic food basket. We tested whether the residuals generated in the model were influenced by the rainfall during the period. The results showed that the model fit is adequate to forecast the price of the basic food basket in Fortaleza. They also showed that the growth of the annual minimum wage adjustments, in general, maintained the purchasing power of this variable. The research showed that the prices of the basic food basket evolved at a lower rate than the evolution of the minimum wage in the period analyzed.