Japan’s wholesale prices just hit a wall that policymakers were hoping to avoid. The Corporate Goods Price Index, the Bank of Japan’s key measure of what companies charge each other for goods, climbed 6.3% year-over-year in May 2026. That’s a sharp acceleration from April’s already elevated 4.9% reading and the fastest pace of increase since March 2023.
Oil shock ripples through Japan’s supply chains
The Bank of Japan released the May CGPI data on June 10, and the numbers tell a story of compounding pressure. On a month-over-month basis, corporate goods prices rose 0.9% in May. That followed a 2.3% monthly jump in April, which was the largest single-month increase since April 2014.
Crude oil and naphtha prices are doing the heavy lifting here. The Iran conflict has disrupted energy markets in ways that go well beyond simple supply concerns. It has introduced a persistent geopolitical risk premium into oil pricing that shows no signs of fading. For Japan, which relies on Middle Eastern energy imports more than most developed economies, this is an especially acute problem.
Tokyo’s policy response takes shape
