A look at central bank assets as a share of national output reveals stark differences in how aggressively major economies have used monetary policy tools over the past two decades.
Not all central banks are created equal. While most set interest rates, some have gone much further — building up vast holdings of government bonds and other assets to support their economies. Measuring those holdings against the size of each country’s economy shows just how differently central banks around the world have approached their role.
Japan stands out as the clearest example of an outsized balance sheet. The Bank of Japan has spent decades buying assets to fight persistently low inflation and sluggish growth, pushing its holdings to a level that rivals or exceeds the entire annual output of the Japanese economy. That ratio — central bank assets divided by gross domestic product, or GDP — is a common way to gauge how deeply a central bank has inserted itself into financial markets.
European central banks also tend to show elevated ratios. The European Central Bank expanded its balance sheet sharply during the eurozone debt crisis of the early 2010s and again during the pandemic, buying bonds to keep borrowing costs low across member countries. Switzerland’s central bank, which actively buys foreign assets to manage its currency, also ranks among the largest relative to its economy.
The U.S. Federal Reserve, by contrast, sits at a more moderate level despite having grown its balance sheet significantly through multiple rounds of quantitative easing — the policy of buying bonds to push down long-term interest rates. The U.S. economy is simply large enough that even trillions of dollars in holdings represent a smaller share of GDP than in many smaller, more export-oriented economies.
Emerging-market central banks generally hold smaller balance sheets relative to GDP. They tend to rely more on traditional interest-rate tools and have less capacity to absorb large-scale asset purchases without triggering concerns about currency stability or inflation.
The comparisons matter now because many central banks are in the process of shrinking their balance sheets — a process called quantitative tightening, or QT — as they pull back from pandemic-era stimulus. How quickly and how far each bank can reduce its holdings without disrupting bond markets is one of the more closely watched questions in global finance. Countries where the central bank owns a very large share of the government bond market face a particularly delicate task.
Balance sheet size alone does not determine a central bank’s effectiveness, but it does shape the risks and constraints policymakers face as they navigate the path back to more normal monetary conditions.
