Today, it seems to be an article of faith among US policymakers and many economists that the world’s appetite for dollar debt is virtually insatiable. But a modernization of China’s exchange-rate arrangements could deal the dollar’s status a painful blow.

CAMBRIDGE – The mighty US dollar continues to reign supreme in global markets. But the greenback’s dominance may well be more fragile than it appears, because expected future changes in China’s exchange-rate regime are likely to trigger a significant shift in the international monetary order.

For many reasons, the Chinese authorities will probably someday stop pegging the renminbi to a basket of currencies, and shift to a modern inflation-targeting regime under which they allow the exchange rate to fluctuate much more freely, especially against the dollar. When that happens, expect most of Asia to follow China. In due time, the dollar, currently the anchor currency for roughly two-thirds of world GDP, could lose nearly half its weight.

Considering how much the United States relies on the dollar’s special status – or what then-French Finance Minister Valéry Giscard d’Estaing famously called America’s “exorbitant privilege” – to fund massive public and private borrowing, the impact of such a shift could be significant. Given that the US has been aggressively using deficit financing to combat the economic ravages of COVID-19, the sustainability of its debt might be called into question.

The long-standing argument for a more flexible Chinese currency is that China is simply too big to let its economy dance to the US Federal Reserve’s tune, even if Chinese capital controls provide some measure of insulation. China’s GDP (measured at international prices) surpassed that of the US back in 2014 and is still growing far faster than the US and Europe, making the case for greater exchange-rate flexibility increasingly compelling.

A more recent argument is that the dollar’s centrality gives the US government too much access to global transactions information. This is also a major concern in Europe. In principle, dollar transactions could be cleared anywhere in the world, but US banks and clearing houses have a significant natural advantage, because they can be implicitly (or explicitly) backed by the Fed, which has unlimited capacity to issue currency in a crisis. In comparison, any dollar clearing house outside the US will always be more subject to crises of confidence – a problem with which even the eurozone has struggled.