【英文】大西洋理事会报告：欧元和美元的国际作用：永远领先？（25页）

Academic work5 has established that once a dominant currency6 is in place, there are powerful stabilizing forces and network efects in play that perpetuate its position unless a major paradigm shift occurs.  Since a country’s foreign exchange reserves need to be of the highest liquidity, central banks will not  change their reserve currency allocation unless they believe that markets in a new reserve currency will  ofer greater liquidity (implying that other market participants are switching their reserve holdings, too). Countries also have an incentive to stabilize their exchange rates vis-à-vis the dominant currency, since  it tends to be a key driver of import price fuctuations. This incentive increases with openness to foreign  trade, giving a further boost to the dollar as trade barriers generally declined in recent decades. Consistent with this trend, many countries have adopted exchange rate policies that tie the value of their  currencies close to the dollar. According to some estimates7 , the number of currencies that are either  directly or indirectly anchored to the dollar (e.g., via currencies that are itself tied to the dollar) is currently  as large as during the Bretton Woods era. 

Moreover, dollar invoicing leads to higher demand for dollar-denominated safe assets, which tends to reduce dollar borrowing costs and, therefore, incentivizes  the fnancing of international trade in dollars. Network efects would of course pertain to any international currency that gained the status of a dominant currency, and it is not a given that the dollar and euro will remain forever in the lead. Transitions  from one dominant reserve currency to another have occurred in the past, usually over lengthy time  intervals and in connection with major geopolitical transitions (see below).Unit of account. A major change in the denomination of international transactions, whether in  trade or fnancial instruments, has been the introduction of the euro in 1999. Taking on the role of  its predecessor currencies, the euro assumed a large share of international payments right from  the start but has failed to make signifcant headway outside of Europe. As seen above, the euro  rivals the dollar in SWIFT payments, and it also accounts for close to 80 percent of trade invoicing  within Europe and parts of Africa, but its role in the rest of the world is still small (Figure 2). Moreover, it has become less of an anchor currency8  for other countries following the euro area crisis a  decade ago.