Ueda links Japan's enduring surplus to corporate saving

Japan's current account surplus generally held at 2–4 percent of GDP for roughly four decades, Ueda said.

Goods trade moved from a surplus exceeding 4 percent in the mid-1980s to deficit; primary income now exceeds 6 percent.

Corporate saving offset falling household saving and persistent fiscal deficits.

After investment peaked around 1990, firms cut capital spending and repaid debt from the late 1990s through the early 2010s.

They remained net savers after repairing their balance sheets.

Ueda traced the investment boom partly to easing after the Plaza Accord and domestic-demand measures in the 1986 Maekawa Report.

He compared Japan with Britain, where foreign investment income approached 8 percent of national income around the turn of the 20th century.

Outward foreign direct investment overtook portfolio investment after 2012, with returns above 8 percent for much of the post-adjustment era.

Direct investment's share of capital outflows rose from 21.0 percent in 1996–2011 to 46.5 percent in 2012–2025; portfolio investment fell from 53.9 to 26.2 percent.

Retained overseas earnings counted as Japanese saving and fresh investment abroad.

Ueda rejected labor scarcity as the earlier driver: the output gap was almost continuously negative in 1993–2012 and unemployment averaged well above 3 percent.

Aging instead depressed domestic growth expectations.