“Unintended Consequences provides a provocative interpretation of the causes of the global financial crisis and the policies needed to return to rapid growth. Whether you agree or not, this analysis is well worth reading.” - Nouriel Roubini, New York University; Chairman, Roubini Global Economics
“…serious thinking for serious thinkers. …a thought-provoking blueprint for growing middle- and working-class incomes.” - Mitt Romney, former Governor of Massachusetts
“There are an amazing number of good ideas and interesting points made in Unintended Consequences. The thinking underlying it, and the obvious depth of understanding of the author, are very impressive.” - Steven Levitt, coauthor of Freakonomics; 2004 John Bates Clark Medal
“…a fresh argument for the productive value of inequality.” - David Autor, Professor of Economics, Massachusetts Institute of Technology
“…challenges misconceptions that distort our economic debates.” - Arthur Brooks, President of the American Enterprise Institute
“…a must-read for serious students of economic policy.” - Glenn Hubbard, Dean, Columbia Business School, and former Chairman of the Council of Economic Advisers
“A full-throated defense of economic dynamism.” - The Wall Street Journal
“…reminds us that inequality sends a signal of what society lacks most, in America’s case, entrepreneurship and risk taking.” - Lawrence Lindsey, CEO, The Lindsey Group, former Director of the National Economic Council
“…challenges misconceptions that distort our economic debates.” - Arthur Brooks, President of the American Enterprise Institute
“…a fresh argument for the productive value of inequality.” - David Autor, Professor of Economics, Massachusetts Institute of Technology
“Unintended Consequences should be read by anyone who takes for granted the superiority of progressive taxation and has not thought carefully about the trade-offs involved.” - The New Republic
“…a comprehensive explanation of the modern economy.” - Julian Robertson, Founder, Tiger Management
AI Summary.Japan's consolidated public sector has liabilities of 255% of GDP, with asset purchases having shortened their duration and bank reserves at the Bank of Japan — floating-rate liabilities — worth 75.5% of GDP, down from 90.7%. Its largely unhedged 56%-of-GDP position in foreign securities and 50%-of-GDP equity holdings would take losses if the yen appreciates and real rates climb.
Hanno LustigThe Two Cents
Date Posted:
Japan’s public sector has “acted as the world’s largest currency carry trader,” borrowing short at below-market rates to buy foreign stocks and bonds unhedged. A rise in the Yen and/or Japanese rates would cause large losses on Tokyo’s balance sheet.
Is Japan's public balance sheet exposed to yen appreciation and rising rates?
Core argument: Japan's consolidated public sector has issued total liabilities worth 255% of GDP, and large-scale asset purchases have sharply shortened the duration of those liabilities.
The consolidated Japanese public sector has issued total liabilities worth 255% of GDP. The large-scale asset purchases have dramatically shortened the duration of those liabilities. Bank reserves held at the BoJ — floating-rate liabilities — are worth 75.5% of GDP in 2025Q3, down from 90.7% in early 2024. On the asset side, the public sector has a long position of 56% of GDP in foreign securities, largely unhedged. The massive depreciation of the JPY has provided a nice fiscal tail wind. As the BoJ raises short rates and lets the long end of the yield curve snap back, the appreciation of the JPY would cause large losses on the asset side. In addition, the public sector has another 50% of GDP invested in equities, long-duration assets that will be marked down as real rates climb.
Takeaways by Macro Roundup® AI
Japan's consolidated public sector has issued total liabilities worth 255% of GDP, and large-scale asset purchases have sharply shortened the duration of those liabilities.
Bank reserves held at the Bank of Japan, a floating-rate liability, stand at 75.5% of GDP in 2025Q3, down from 90.7% in early 2024.
Japan's public sector holds a largely unhedged long position of 56% of GDP in foreign securities plus another 50% of GDP in equities, so yen appreciation and climbing real rates would generate large asset-side losses.
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Yen Intervention = US Self-Preservation— Japan's two traditional options for supporting a weak yen — much higher Japanese interest rates or large sales of dollars and US Treasuries — would both pressure US yields, as Japan holds about $1tn of Treasuries. US willingness to back Japan via its exchange stabilization fund and the Federal Reserve's international repo facility suggests officials see that risk.
Japan’s Debt Puzzle: Sovereign Wealth Fund from Borrowed Money— Japan's public sector operates as a highly leveraged sovereign wealth fund, funding risky assets by borrowing from banks and depositors at below-market rates, with returns sustaining its debt-to-GDP ratio above 200% without primary surpluses. The authors argue the resulting duration and currency mismatches expose Japan to mark-to-market losses that could trigger a fiscal crisis or a run on the yen.
