Singapore publishes two inflation rates each month, and they seldom agree. In September 2022 headline inflation was 7.5% while MAS Core Inflation was 5.3%; by October 2024 core was the higher of the two, at 2.1% against 1.2%.
Core inflation is calculated from a smaller basket. It leaves out just over a third of what the headline index weighs, and what it leaves out is housing and cars.
What is left out
MAS describes the measure in one line:
"MAS Core Inflation excludes the costs of accommodation and private transport from CPI-All Items inflation."
In the Consumer Price Index rebased to 2024, those two groups carry a lot of weight. Out of 10,000 points, accommodation is 2,656 and private transport is 906 — 3,562 together, or 35.6% of the basket. Core inflation is computed from the remaining 64.4% or so.
Singapore does the opposite of the usual convention elsewhere. Many central banks' core measures drop food and energy; MAS keeps both, on the reasoning that its policy "can directly influence the pass-through from global prices to domestic prices."
Why MAS removes housing and cars
The stated reason is that these two items "tend to be significantly influenced by supply-side administrative policies and are volatile." Car prices move with the Certificate of Entitlement quota; MAS notes that private transport costs "fluctuate according to prices of 'Certificates of Entitlement' determined under the vehicle quota system".
The accommodation argument is more interesting, because it turns on what the number actually measures.
Most of "accommodation" is not money anyone pays
Of accommodation's 2,656 points, 2,138 are imputed rentals for housing. Actual rent is 294 and maintenance and repairs 224. The Department of Statistics explains imputed rent this way:
"computed based on the imputed rental concept under the rental equivalence method, i.e. proxied by market rentals of similar properties… as though the homeowner were renting it from themselves."
So when market rents rise, the CPI records a cost increase for every owner-occupier, even though an owner's monthly outgoings have not changed. The statistics department says as much: "Imputed rentals have no impact on the cash expenditure of most households in Singapore as they already own their homes." In 2025, 91.2% of resident households owned their home. And only 36.3% of resident households had a car in the 2023 Household Expenditure Survey.
MAS's argument follows from those figures. For most households the excluded housing cost is not paid in cash, and most households do not own a car at all; in MAS's words, imputed rentals "do not reflect the cash outlays of the large majority of households who own their homes".
The objection, and why it still matters
For a household that rents, or is buying a car this year, the excluded items are real money and often the largest numbers on the budget. Those households are the minority, but they are the ones most likely to feel that the published core figure understates their year.
Private transport is also not only COE. Petrol carries 174 of its 906 points, and MAS's release on July 2026 prices attributed the latest movement in the group to petrol and diesel, which every driver pays whatever their COE.
The gap runs both ways
Core inflation has been the higher of the two about as often as the lower.
- March 2022: headline 5.4%, core 2.9% — core lower by 2.5 points.
- 2022 as a whole: 6.1% against 4.1%.
- January 2019: headline 0.4%, core 1.9% — core higher by 1.5 points.
- September 2024: 1.9% against 2.8%; 2024 as a whole: 2.4% against 2.8%.
Which one is higher depends on whether housing and cars are rising faster than the rest of the basket. In September 2022, private transport prices were up 22.3% on a year earlier.
What MAS actually does with it
MAS does not set interest rates. It manages the Singapore dollar against a basket of currencies, and says it "uses the nominal exchange rate as the intermediate target of monetary policy". Nor does it publish a formal inflation target:
"MAS does not have an explicit inflation target. Nevertheless, MAS has concluded that, on average, a core inflation rate of just under 2%… is consistent with overall price stability."
Core inflation is the measure it describes as the one it monitors most closely. In its July 2026 statement MAS said it would "increase the rate of appreciation of the policy band very slightly", and projected both core and headline inflation at 1.5% to 2.5% for 2026.
Neither number is yours
Headline inflation includes a large imputed cost that owner-occupiers never pay in cash, which can make their budgets look tighter than they are; core leaves out the rent a tenant does pay. Both are averages over a basket weighted by aggregate household spending, and neither is anyone's personal rate.
What to do with it
An owner-occupier without a car will usually find core closer to their own experience. A tenant, or someone about to buy a car, learns more from the accommodation and private transport series themselves than from either summary figure.
The statistics department also publishes two in-between series that are rarely quoted: all items less imputed rentals, which was 2.7% in July 2026, and all items less accommodation, at 2.8%. For an owner-occupier who drives, the first is arguably the most relevant of the four.
Where this comes from
The definitions and rationale are from the Monetary Authority of Singapore's monetary policy FAQ, its Macroeconomic Review, its Monetary Policy Statement of 27 July 2026 and its consumer price release of 24 August 2026. The weights are from the Department of Statistics' weighting pattern for the 2024-based CPI; the monthly and annual rates are from its TableBuilder series for CPI-All Items and MAS Core Inflation, updated 24 August 2026; home ownership and car ownership are from its household tables. All were read on 17 September 2026.
The 35.6% figure is the sum of the two published weights, 2,656 and 906, out of 10,000. July 2026 was the latest month in the statistics department's series when this was written.
