ON THE EFFECT OF CONSUMER PRICE INDEX INFLATION ON FOOD SECURITY AND PUBLIC HEALTH OUTCOMES IN NIGERIA: A TIME SERIES APPROACH

Abstract

Persistent inflation remains a major macroeconomic challenge in Nigeria, with rising consumer
prices—particularly food prices—posing serious threats to food security and public health
outcomes. This study investigates the dynamic behavior of Nigeria’s Consumer Price Index (CPI)
and examines its implications for food security and public health using a time series approach.
Monthly CPI data were analyzed within the Box–Jenkins framework, employing Autoregressive
Integrated Moving Average (ARIMA) models. Stationarity was assessed using Augmented
Dickey–Fuller (ADF) and KPSS tests, while model adequacy was evaluated through diagnostic
checks including residual autocorrelation, heteroscedasticity, and normality tests. The results
indicate that the CPI series is integrated of order one, I(1), and the ARIMA(3,1,2) model provides
the best fit based on information criteria. Forecasts from the selected model suggest a mild
deceleration in CPI inflation over the forecast horizon, although uncertainty widens over time.
From a food security and public health perspective, persistent CPI inflation—especially food
inflation—erodes household purchasing power, reduces dietary quality, and heightens risks of
malnutrition, maternal and child morbidity, and social vulnerability. The study underscores that
inflation is not merely a macroeconomic indicator but a critical determinant of population health
and human security. It recommends strengthened inflation monitoring, improved agricultural
productivity, and integrated economic–health policy responses to mitigate the adverse welfare
effects of rising prices in Nigeria.
Keywords: Inflation, Consumer Price Index, Food Security, Public Health, Time Series