May 2026 consumer prices showed mixed signals: the headline CPI rose 1.5% year‑on‑year (y/y), accelerating 0.1 percentage point from April (1.4%), while the measure of underlying inflation, core‑core CPI (excluding fresh food and energy), fell to 1.8%, down 0.1 percentage point from April (1.9%). The divergence among the three CPI measures reflects two differing forces: energy prices providing upward support to the headline index, and a deceleration in underlying inflationary pressure. With the Corporate Goods Price Index (CGPI) essentially flat month‑on‑month, upstream‑to‑downstream passthrough pressures are easing, but the BOJ (Bank of Japan)’s trimmed mean remains at 2.8% (unchanged from the prior month), indicating that the underlying trend—once transitory factors are removed—remains relatively robust.
According to the Statistics Bureau of Japan (MIC), the headline CPI stood at 113.5 (2020=100) in May 2026, up 0.5 points from 113.0 in April. This represents a 1.5% y/y increase, 0.1 percentage point higher than the prior month (1.4%). Core CPI (excluding fresh food) held steady at 1.4% y/y in May, while core‑core CPI (excluding fresh food and energy) decreased to 1.8% y/y from 1.9% in April.
From these three indicators we can infer the following structure: the acceleration in headline CPI is mainly attributable to supportive energy price movements, while the flat core CPI suggests limited volatility in fresh food prices. The most important point is the turn lower in core‑core CPI, which suggests that the underlying inflationary momentum may be entering a deceleration phase.
Looking at the past 12 months, core‑core CPI peaked at 2.9% in December 2025 and has since fallen: 2.6% in January 2026, 2.5% in February, 2.4% in March, 1.9% in April, and 1.8% in May. This clear downtrend—1.1 percentage points over six months—indicates a continued adjustment from the high‑inflation episode in the second half of 2025 when rates were in the 3% range.
Against the BOJ (Bank of Japan)’s price stability target of 2% y/y, core CPI at 1.4% in May 2026 is 0.6 percentage point below target. This gap is unchanged from April (core CPI 1.4%, gap 0.6ppt), indicating stalled convergence toward the target. More concerning is the six‑month path of core CPI: after reaching 2.4% in December 2025 and 2.0% in January 2026 (briefly at target), it fell to 1.6% in February, 1.8% in March, and has remained at 1.4% in April and May.
Viewed by core‑core CPI, May’s 1.8% is 0.2 percentage point below target and further from the BOJ goal than the prior month (1.9%). Compared with the period from July to October 2025 when core‑core CPI exceeded 3.0%, the decline of more than 1.2 percentage points in just over half a year confirms a rapid slowdown in underlying inflationary pressure.
These developments suggest that much of the price rise seen in late 2025 may have been supported by temporary factors. From the perspective of sustained achievement of the target, there is a risk that rates in the low‑1% range become entrenched.
The BOJ’s trimmed mean indicator of core inflation was 2.8% for April 2026 (May’s figure not yet published), up 0.3 percentage point from March (2.5%). This trimmed mean of 2.8% exceeds April’s core CPI (1.4%) by 1.4 percentage points, widening the gap from the prior month (1.1ppt).
The trimmed mean is a weighted average that excludes the top and bottom 10% of the distribution of CPI item inflation rates, statistically removing transitory influences such as energy and fresh food to reveal the “true” inflation trend. The situation in which the trimmed mean markedly exceeds core CPI can be interpreted in two ways.
First, downward pressure on energy prices may be pulling core CPI lower. Because some energy‑related items are excluded in the trimmed mean calculation, when energy prices are falling the trimmed mean can appear higher than core CPI. Second, underlying price pressures for core goods and services may still be holding in the high‑2% range, implying that underlying inflation could be stronger than the headline CPI measures suggest.
The weighted median was 1.4% in April—equal to core CPI and down 0.3 percentage point from March (1.7%). As the distribution’s median, this indicates a near balance between items rising and those falling. The 1.4 percentage point divergence between the trimmed mean (2.8%) and the weighted median (1.4%) indicates an asymmetric distribution of price changes, where a subset of large‑increase items is pulling up the mean.
Historically, the trimmed mean fell from 2.9% in May 2025 to 2.2% in February 2026, then rose to 2.5% in March and 2.8% in April. This pattern suggests that underlying inflationary pressure weakened temporarily before re‑intensifying, a movement that differs from the downtrend seen in core and core‑core CPI.
BOJ statistics show the Corporate Goods Price Index (CGPI) at 126.5 in May 2026, up 0.1 point from April (126.4). This +0.08% month‑on‑month increase is effectively flat. After a large month‑on‑month rise of +1.2 points (+0.93%) in March 2026, CGPI was flat in April and barely positive in May, indicating a clear slowdown in the pace of upstream price increases.
Month‑to‑month CGPI changes over the past six months were: +3.6 points in December 2025, +1.2 points in January 2026, flat in February, +1.2 points in March, flat in April, and +0.1 point in May. This sequence points to an adjustment phase following the December 2025 spike. CGPI’s level of 126.5 is 8.0 points (5.9%) below December 2025’s 134.5, confirming that price adjustments among firms are progressing.
Pass‑through from CGPI (upstream, inter‑firm prices) to CPI (downstream, consumer prices) typically involves a 3–6 month lag. The March 2026 CGPI surge (+1.2 points month‑on‑month) could therefore influence CPI around August–September 2026, but the flat CGPI readings in April–May suggest limited downstream inflationary pressure in the months ahead.
The Service Producer Price Index (SPPI) was 114.3 in April 2026, up from 113.7 in March (+0.6 point, +0.53% m/m). This follows March’s large increase of +1.5 points (+1.32%). SPPI rose from 112.0 in January 2026 to 114.3 in April—an increase of 2.3 points (2.1%) over three months—indicating that upstream price pressure in services remains stronger than in goods (CGPI).
This divergence between goods and services highlights asymmetry in pass‑through dynamics. While upstream goods prices are adjusting downward, service sector pass‑through driven by wage increases and other costs continues, meaning services could remain an important source of support for future CPI.
According to the Cabinet Office’s Business Conditions Index (CI), the coincident index for April 2026 was 117.9, up 1.1 points from March (116.8). This level equals the January 2026 reading (117.9) and remains at a year‑to‑date high. The coincident index has been rising since a trough of 113.9 in August 2025, increasing 4.0 points (3.5%) over eight months.
The leading index was 115.9 in April, up 0.5 points from March (115.4). Since its low of 104.3 in April 2025, the leading index has risen 11.6 points (11.1%) over one year, signaling strong momentum and suggesting further economic expansion in coming months—implying heightened demand‑side inflationary pressure.
The current situation—coincident index rising while core‑core CPI falls—may appear contradictory. However, it can be interpreted as a balance between demand‑driven upward price pressure and downward pressure from upstream price adjustments. If the recovery in economic activity persists, demand‑side inflationary pressures could become dominant.
BOJ Tankan survey results show the large‑manufacturers’ business conditions Diffusion Index (DI) at +17 in Q1 2026, an improvement of 2 points from +15 in the prior quarter. The outlook DI is +15, 2 points below the current DI (+17) but still in positive territory. The large non‑manufacturing DI is +36, up 2 points from +34 quarter‑on‑quarter, while its outlook DI is +28, an 8‑point decline from the current level.
Mid‑sized manufacturers’ DI was +16, unchanged from the prior quarter, and small manufacturers’ DI was +7, up 1 point from +6. Across firm sizes and sectors, sentiment shows improvement, and the +36 reading for large non‑manufacturers underscores strong service‑sector demand.
Improving business conditions suggest greater scope for firms to pass through cost increases to prices. In a favorable business environment, firms find it easier to reflect rising input and labor costs in selling prices. The relatively stronger non‑manufacturing conditions align with the SPPI increases noted earlier and underlie continued upward pressure on service prices.
Assumed exchange rates in Q1 2026 were ¥150.10 for all firms/all industries and ¥148.91 for large manufacturers, revised from ¥147.06 and ¥146.48 in the prior quarter toward a weaker yen. This weaker‑yen assumption implies import cost pressure that could feed into prices, but the current flat CGPI suggests that exchange‑rate effects on prices have been limited so far.
On the supply side, MOF trade statistics show imports at ¥10,312.9 billion in December 2025, up 9.7% from ¥9,402.9 billion the prior month. This rise in import values likely contributed to the CGPI increase in January 2026 (+1.2 points m/m). However, the subsequent flat CGPI indicates that cost‑push pressure from import prices has cooled.
Tracing the supply‑side transmission—import values → CGPI → CPI—the December 2025 import spike appears to have driven the January 2026 CGPI rise, with effects feeding into CPI around April–July 2026 (a 3–6 month lag). The current flat CGPI therefore points to limited CPI upside from supply shocks in the coming months.
On the demand side, METI’s Commerce Dynamics statistics indicate retail sales of ¥1,272.8 billion in January 2025 (note: original text cited 2025 data), a 4.4% y/y increase. The high growth rate signals resilient consumer demand. Year‑on‑year retail sales over the past six months show an accelerating pattern: September 2024 +0.7%, October +1.3%, November +2.8%, December +3.5%, January 2025 +4.4%, suggesting strengthening demand‑pull inflationary pressure.
The combination of eased supply constraints (flat CGPI) and firm demand (rising retail sales) supports price stabilization. With weaker cost‑push pressure and continued demand, firms may see margin recovery, enabling sustained wage growth. If this virtuous cycle takes hold, demand‑driven stable inflation may be achievable.
TOPIX stood at 4,068.18 as of June 18, 2026, up 175.72 points (4.5%) from 3,892.46 on May 22. The roughly one‑month rise included a retracement to 3,852.38 on June 8, followed by a sharp rebound to 3,999.60 on June 15 and further gains thereafter.
The equity rally reflects expectations of economic recovery and improving corporate earnings. The earlier‑noted rises in the business conditions index, improvements in Tankan DI, and higher retail sales are all consistent with stronger corporate profitability, supporting the stock advance.
In relation to prices, the slowdown in underlying inflation (core‑core CPI at 1.8%) reduces immediate pressure for further BOJ tightening, which is positive for equities. At the same time, the trimmed mean at 2.8% points to a persistent underlying trend and a risk of inflation re‑acceleration, complicating future policy decisions.
The sharp equity rebound in mid‑June likely reflects reduced fears of imminent tightening after confirmation of slowing inflation. Markets may be interpreting the current price environment as a “just right” balance—not too hot, not too cold.
Looking ahead, three scenarios are plausible.
First, underlying inflation continues to decelerate and core CPI remains in the low‑1% range. If the slowdown in upstream price pressure signaled by flat CGPI transmits downstream, CPI inflation may soften further. In this case, the BOJ’s 2% target would remain out of reach and additional rate increases would be difficult to justify. A continued accommodative stance would support the economy, but the risk of a prolonged miss of the price target would rise.
Second, the underlying trend implied by the BOJ’s trimmed mean (2.8%) materializes and core CPI climbs back toward 2%. Service‑price passthrough (SPPI increases), solid retail demand, and expanding economic activity (CI) could combine to produce demand‑driven inflation. Under this scenario, the BOJ would face conditions that warrant consideration of further rate hikes, though timing and magnitude would be critical.
Third, inflation settles in the mid‑1% range. Upstream price adjustments and firm demand balance out, yielding gradual price increases that fall short of 2%. The BOJ would likely maintain current policy while awaiting stronger wage growth to secure sustained inflation.
At present, the third scenario appears most likely. Core CPI at 1.4% and core‑core CPI at 1.8% imply a low risk of returning to deflation but a clear distance from the 2% goal. Although the trimmed mean points to persistent upward pressure, it may take time to transmit to headline CPI measures.
For households, mid‑1% inflation means real purchasing power depends on wage gains. If 2026 spring wage negotiations result in wage increases in the 3% range, real wages would rise and consumption could expand sustainably. Conversely, if inflation exceeds 2% without commensurate wage gains, real purchasing power would deteriorate.
Policy‑wise, the current price environment does not call for hasty rate hikes, but given the trimmed mean’s signal of persistent underlying pressure, the BOJ should cautiously prepare an exit strategy from monetary accommodation. The BOJ must evaluate not only headline CPI but also indicators such as the trimmed mean and SPPI to judge the durability of inflation. Premature tightening risks hindering the economic recovery, while delayed response could allow inflation to accelerate, necessitating sharper tightening later.
Core CPI: Consumer Price Index excluding fresh food. By removing fresh food—an item subject to large weather‑driven volatility—this measure captures underlying price movements. The BOJ uses it in assessing progress toward the 2% y/y price stability target.
Core‑core CPI: Consumer Price Index excluding fresh food and energy. By excluding energy—sensitive to international commodity markets—this indicator measures underlying inflationary pressure that more directly reflects domestic supply and demand conditions.
Corporate Goods Price Index (CGPI): An index capturing the price level of goods traded between firms. CGPI reflects upstream (inter‑firm) price dynamics and typically leads consumer prices (CPI). Published by the BOJ (Bank of Japan).
Service Producer Price Index (SPPI): An index of prices for services traded between firms. SPPI covers sectors such as transportation, communications, advertising, and leasing, capturing upstream price movements in services. Published by the BOJ.
Trimmed mean: A weighted average of CPI item inflation rates that excludes the top and bottom 10% of the distribution. By statistically removing transitory factors such as energy and fresh food, it aims to reveal the underlying inflation trend. Published by the BOJ.
Weighted median: The weighted median of the distribution of CPI item inflation rates. Less sensitive to outliers, it indicates the central tendency of price changes. Published by the BOJ.
Business Conditions Index (CI): An index indicating quantitative changes in economic conditions. It comprises a leading index (predicting the economy several months ahead), a coincident index (showing current conditions), and a lagging index (confirmatory). Published by the Cabinet Office.
Business Conditions DI: Diffusion Index (DI) from the BOJ Tankan survey that measures corporate sentiment. Calculated as the percentage of firms reporting 'favorable' conditions minus the percentage reporting 'unfavorable' conditions; higher positive values indicate stronger sentiment.
Price pass‑through: The process by which increases in costs—such as raw materials or labor—are reflected in selling prices. Pass‑through from CGPI (upstream) to CPI (downstream) typically involves a 3–6 month lag.
Demand‑pull inflation: Inflation caused when demand outpaces supply, typically observed during economic expansions and often associated with sustained, growth‑accompanied price increases.
Cost‑push inflation: Inflation driven by increases in supply‑side costs—such as raw materials or energy—potentially reducing real incomes and adversely affecting economic activity.
This column was automatically generated by AI integrating Cabinet Office GDP data, Bank of Japan statistics, e-Stat public statistics, and market data as a macroeconomic analysis resource. This is not a recommendation to invest in any specific security. Please make investment decisions at your own responsibility and consult professionals as needed.