数字幻觉：总债务 vs 净债务
日本政府债务在 2023 年达到 GDP 的 226%，几乎是法国或英国的两倍，但日本却能以极低的利率持续借贷且未爆发危机。经济学家 Tim Dou 和 Lustig 指出，秘诀在于我们看错了数字。
与西方国家不同，日本的综合政府（Consolidated Government：包括央行和公共养老基金等机构）持有一个巨大的金融资产组合。到 2024 年，这些股票和债券资产价值约占 GDP 的 192%。虽然日本的总债务（Gross Debt）确实很高，但扣除这些金融资产后的净债务（Net Debt：总债务减去金融资产）仅约为 GDP 的 77%。相比之下，由于美英等国持有的资产远少于日本，日本的净债务实际上是这三国中最低的。
Original English Source
We all know that Japan has the highest government debt in the world, at 226% of GDP in 2023. That that is almost double that of France or the UK... Investors seem willing to keep lending Japan a lot of money at much lower interest rates than other countries... Actually, everyone has just been looking at the wrong number... Japan's consolidated government, which includes institutions like the central Bank and public pension funds, holds a massive financial portfolio of stocks and bonds that was worth about 192% of GDP in 2020 fourth... netting those two out means that Japan's true government debt suddenly looks far less alarming. Closer to 77% of GDP.国家对冲基金：借日元，投全球
日本政府的运作模式并非简单的“花钱给老人”，而是像一个巨型的主权财富基金（Sovereign Wealth Fund：国家拥有的投资机构）。更准确地说，日本政府运作得像一个巨大的套利对冲基金。
它以极低的利率向日本国民借入日元，然后将资金投入全球，换成美元资产以获取高额回报。这解释了为什么尽管日本国内经济规模缩水，它依然是全球最大的海外资产持有国。它是美国债务最大的持有者，规模甚至超过了中国。这种“借低投高”的套利交易（Carry Trade：利用不同货币间的利率差进行借贷和投资）成为了支撑日本财政的关键。
Original English Source
Japan's government pays a lower interest rate and does not have massive inflation problems simply because, rather than just spending on the elderly, the Japanese state has been buying a lot of financial assets and especially foreign assets... This is why I, chin, do and Lustig refer to the Japanese government in their paper as a giant sovereign wealth fund... I would actually argue that Japan's government complex has become like a dairy trading giant, hedge fund borrowing from people in yen that low interest rates and lending it out to the world, investing in the world in dollars at a very high interest rate.历史演变：从公共银行到全球玩家
日本政府这一结构的演变分为两个阶段。在战后经济奇迹时期，政府通过日本邮政（Japan Post）和财政投融资计划（FILF: Fiscal Investment and Loan Fund）充当“巨型公共银行”。通过法律手段压低储蓄利率，获取廉价资金以重建工业。这种模式下的债务和投资在官方财政数据中大多是隐形的。
20 世纪 90 年代泡沫破裂后，日本转向西方自由市场模式，削减了廉价的存款融资渠道并私有化了日本邮政。面对日益严重的人口危机和社保开支，日本政府没有选择紧缩政策，而是转型成了“对冲基金”。它不再只是卖出养老金资产，而是大规模发行国债。日本央行通过量化宽松购买这些国债，创造出极低利率的储备资金。实际上，政府再次以超低利率向国民借钱，只是这次是通过央行间接完成。
Original English Source
During the postwar economic miracle... the Japanese government complex essentially already acted like a giant bank via the government owned Japan Post... after the Japanese economic miracle stopped working, Japan became more and more convinced that Western free market ideas were the answer... Japan in the early 2000 was the first country to start facing a serious, serious demographic crisis... instead of having stopped being a giant national bank, it then became a giant hedge fund... rather than selling pension assets, it started borrowing on a massive scale... Japan government was again borrowing from the Japanese people at very low interest rates. But now, rather than doing it via national banks like Japan Post, it did so indirectly via the central bank.幸运的赌局：汇率贬值带来的“财富增值”
这种“对冲基金”模式之所以能成功，很大程度上源于日本惊人的“运气”。其成功基于三个要素：外债利差、海外资产价格上涨，以及最重要的——日元贬值。
以养老基金购买 100 美元美债为例，如果汇率从 1:100 变为 1:150，即便投资本身没有增值，换回日元时也会产生 50% 的汇率收益。正是这种效应，使得日本的净债务从 2012 年的 118% 下降到了今天的 77%。日本并非秘密地奉行审慎财政，而是通过增加借贷去赌海外资产上涨，并且赌赢了。
Original English Source
First, it reignited the old Japan government complex profit machine because they were borrowing very cheaply via the central bank... Second, while asset prices in Japan would go up by quite a bit, asset prices abroad would go up by way more than that. And finally, third... the Japanese yen would actually fall by a lot... Imagine that a state owned pension fund would buy 100 worth of U.S. Treasury bonds in 2013... it paid about ¥10,000 for these bonds... in 2024, when the exchange rate is roughly ¥150 per dollar... these same bonds are worth 15 K in yen. And that's a 50% gain purely from the exchange rate moving.通胀归来：对冲基金模式的终极威胁
然而，这种幸运模式正面临两大风险：地缘政治与通胀。如果全球化终结导致海外资产损失，日本债务率将瞬间飙升。更迫在眉睫的是，持续贬值的日元推高了进口成本，导致通胀回归。
著名的 Charles Goodhart 教授预言，当人口老龄化到一定程度，人们将从“生产者和储蓄者”转变为“消费者”，必然推高通胀。通常央行会通过提高利率来对抗通胀，但对于日本这个“国家对冲基金”来说，加息的代价极其沉重：它会破坏低成本借贷的基础，缩小利差。日本正陷入一个棘手的困境：为了控制债务，它必须维持超低利率和弱势日元，但这也意味着必须忍受日益严重的物价上涨。经过几十年的通缩，日本再次迎来了通胀，这预示着旧模式可能已走到尽头。
Original English Source
The first is obvious it's geopolitics... if the world completely globalize and Japan loses its foreign assets completely, then Japan's debt to GDP suddenly... goes up from 77% to about 140% of GDP... The second more probable risk is inflation... if the yen goes down all the time, imports become more expensive... causing inflation... Charles Goodhart from the London School of Economics has predicted that once populations get too old, they will likely face more and more inflation... If it wants to keep its debt under control, not only does it need to control spending, it also needs to keep interest rates very low indeed, and it will need to keep the yen relatively weak... Japan will soon be known as the land of the rising inflation.📌 文中提及的人物和组织
人物: Tim Dou, Hanno Lustig, Charles Goodhart
公司/组织: Bank of Japan, Japan Post