Nigeria’s National Bureau of Statistics (NBS) has projected a temporary rise in the country’s December 2025 inflation rate, which it described as an “artificial spike” driven by statistical calculations rather than underlying economic pressures.
Speaking on Monday at a stakeholder engagement jointly organised by NBS and the Nigerian Economic Summit Group (NESG), Statistician-General Adeyemi Adeniran explained that the increase would result from the use of December 2024 as the new base period, which was set at 100 following a rebasing exercise. “It is important to state that the base effect is a common feature in statistical practice when comparing yearly or monthly data, especially when transitioning from high or low prices in a previous period to the current period,” Adeniran said.
The rebasing of the Consumer Price Index (CPI), now tracking 934 products up from 700, was intended to better reflect changes in Nigerian consumption patterns over the past 15 years. NBS Director of Prices and Trade, Ayo Anthony, noted that more than 400 new items were added to the basket while 200 older items were removed. He cautioned that linking the new CPI series with the previous one could temporarily distort December inflation figures, but said the application of “normalisation” techniques would correct for this base effect.
Anthony emphasised that the projected spike is purely arithmetic and does not indicate a sudden rise in the cost of living. He reassured stakeholders that the base effect would not influence inflation readings from January 2026 onwards, allowing policymakers, investors, and businesses to rely on accurate data for economic decision-making.
Economists said the clarification is important, as misleading inflation signals can affect monetary policy, wage negotiations, and public confidence in economic institutions. Accurate CPI data helps the Central Bank of Nigeria, fiscal authorities, and private-sector actors monitor price stability and structural economic changes. Misinterpretation of December’s figures could have led to unnecessary market anxiety or policy missteps.
The NBS is expected to release the official December 2025 inflation figures later this week, which, after normalisation, should reflect the true state of price pressures in the economy.




