Producer Price Index YoY

Producer Price Index YoY measures the yearly change in Japan factory-gate goods prices. The index is the PPI part of the Corporate Goods Price Index (CGPI), a Bank of Japan monthly survey of corporate-sector goods. It covers domestically produced and traded goods except exports routed through the domestic market, measured at producer shipment stage. The producer-stage share exceeds 95 percent of weight as of March 2022.

It excludes household consumer prices, services prices, retail margins, and the export and import goods in sibling indexes. The Wholesale Price Index became this collective index on December 9, 2002.

Reporting firms receive questionnaires at the start of the next month, and late prices enter indexes one or more months later. Preliminary figures appear on the Bank of Japan website at 8:50 JST on the 8th business day after the month, or the 9th for September.

Each release brings the PPI with the summer electricity split, export and import indexes in yen and contract currency, and the reference rate. It also shows index levels with monthly and yearly changes and contributors. Preliminary data stay open for revision over the next 3 months, and September revisions reach back to January of the prior year. Large moves in All Commodities can trigger unscheduled revisions, and the publisher states no target or threshold.

The PPI has 5 major groups split into 23 groups, and the 6 clusters below cover them, with energy often swinging the result.

• Petroleum and coal products: fuel prices such as gasoline, gas oil, and heavy fuel oils.
• Electric power, gas and water: prices for electricity and gas supply, with a summer extra-charge split.
• Chemicals and related products: xylene, benzene, and styrene monomer prices.
• Iron and steel, nonferrous metals, scrap and waste: steel, copper, aluminum, and iron and copper scrap prices.
• Electrical machinery and equipment, production machinery, transportation equipment: control gear, semiconductor equipment, and engine parts.
• Beverages and foods, agriculture, forestry and fishery products, textile products: dairy, snacks, rice, eggs, and outerwear.

In September 2023 the PPI fell 0.3 percent on the month to 119.3 while yearly growth slowed to 2.0 percent. The preliminary reading was released October 12, 2023, after 0.3 percent and 3.3 percent in August, revised.

Petroleum and coal products cut 0.30 points and electric power, gas and water cut 0.15 points, while chemicals and farm goods each added 0.05 points. Gasoline, gas oil, heavy oils, electricity and gas dragged, while xylene, benzene, rice and chicken eggs lifted. Exports rose 0.5 percent and imports rose 0.6 percent on the month in contract currency, while yen-based imports fell 14.0 percent on the year.

1. Fixed-weight Laspeyres base: set 2020 average prices to 100 and fix value weights from average 2019 to 2020 trade values.

Weights draw on the manufacturing census and trade statistics.

1. Sample index: divide each reported price by its own 2020 average price.
2. Commodity average: weight each sample index by sample weight, sum them and divide by commodity weight.

For example, A at 210/200 = 105 and B at 102/100 = 102 give (105 x 600 + 102 x 400) / 1,000 = 103.8.

1. Higher groups: repeat the same weighted sum over all member samples divided by group weight.
2. Chain-weighted reference: cover higher groups only, reset to 100 each December and compound later rate changes.
3. Gaps and quality: missing prices use the prior-month price and replaced items use one of 9 quality fixes.
4. Currency: export prices are FOB at loading and import prices CIF at unloading, each in yen and contract currency.

Foreign samples convert at the monthly-average middle rate.

1. Seasons: the index has no seasonal adjustment beyond in-season averages and the summer electricity split.