NBS projects temporary ‘artificial spike’ in December 2025 inflation
The National Bureau of Statistics (NBS) has projected a temporary “artificial spike” in Nigeria’s December 2025 inflation rate.
Adeyemi Adeniran, statistician-general of the federation, spoke on Monday during a stakeholder engagement on the December 2025 Consumer Price Index (CPI) and inflation organised by NBS and the Nigerian Economic Summit Group (NESG)
He said the spike would result from the base effect of December 2024, which was equated to 100 following the rebasing.
“This artificial spike is as a result of the base effect of December 2024, which is equated to 100, following the rebasing exercise,” Adeniran said.
“It is important to state that the base effect is a common feature in statistical practise when comparing yearly or monthly data, especially if you are coming from a high or low prices from a base period to the current period.
“It is not something unexpected, it is not something unusual. Base effect is common in statistical exercise.”
The statistician-general added that the spike is purely arithmetic—driven by computations and comparisons—and does not reflect structural changes in the economy.
During the technical presentation, Ayo Anthony, director of prices and trade at NBS, explained that the bureau’s CPI basket now includes 934 products, up from 700 in the previous basket, reflecting changing consumption patterns over the last 15 years.
He said over 400 new products were added, while 200 were removed as they were no longer commonly consumed.
Anthony noted that linking the new CPI with the previous index can create temporary distortions in the December figures.
“If the CPI for December is projected at 131.2, derived from November’s 130.5, it does not represent the true state of the economy. This is why we apply normalisation to remove the base effect,” the director said.
Normalisation, according to Anthony, involves maximising the index reference period.
“If we don’t normalise, the year-on-year inflation in December will not be speaking to the true reality of the inflationary pressure of the economy,” he added.
The director assured stakeholders that the base effect will not influence inflation figures from January 2026 onward.
NBS said Nigeria’s inflation rate for December 2025 will be announced this week.
