Nigeria’s National Bureau of Statistics (NBS) and the Central Bank of Nigeria (CBN) have agreed to adjust how inflation is calculated and presented after officials warned that December’s headline inflation rate could spike sharply for technical reasons, potentially alarming markets despite limited underlying change in consumer prices.
The expected jump stems from a base-effect distortion linked to Nigeria’s recent CPI rebasing, which set December 2024 as the new reference point. NBS officials say that using a single-month reference period in an environment that saw sharp price increases around late 2024 can mechanically inflate the year-on-year comparison for December 2025, even if month-to-month price pressures have not surged.
Economists cited by Bloomberg and Reuters have projected that the December print could more than double from November’s 14.45% — with some projections clustering around 30% to 31% — largely reflecting methodology effects rather than a sudden deterioration in inflation dynamics. NBS has stressed that the widely circulated numbers are projections, and that any spike should be interpreted as a one-off statistical artefact.
To improve transparency, NBS says it will modify reporting so the published data better reflect underlying price trends. Reuters reported that the bureau plans to replace the single-month reference period with a 12-month reference period for 2024, arguing that Nigeria’s volatility makes the one-month approach unsuitable even if it is used elsewhere. Bloomberg reported that NBS also intends to publish two inflation readings for December—one reflecting economic fundamentals and another capturing the mechanically inflated headline—so users can see both the “raw” outcome of the methodology and the “normalized” measure.
The recalibration matters because inflation is central to policy and investor expectations. The CBN relies on inflation trends to calibrate interest rates and liquidity conditions, while domestic bond and FX markets closely track NBS prints for signals about real yields and policy direction. Analysts have warned that an uncontextualized spike could tighten financial conditions unnecessarily by spooking markets and reshaping rate expectations.
NBS officials say the goal is not to mask price pressures but to ensure the statistical presentation is not dominated by rebasing distortions. The bureau expects figures from January 2026 to “normalize” and better track actual market conditions.
