Michael Pettis explains why the US dollar as reserve currency is a burden rather than a privilege for the US:
Historically, neither Europe nor Japan, and certainly not China, have been willing to permit foreigners to purchase significant amounts of government bonds for reserve purposes. When the PBoC tried to accumulate yen three years ago, for example, rather than welcome the friendly Chinese gesture granting the Bank of Japan some of the exorbitant privilege enjoyed by the Fed, the Japanese government demanded that the PBoC stop buying. The reason is because PBoC buying would force up the value of the yen by just enough to reduce Japan’s current account surplus by an amount exactly equal to PBoC purchases. This, after all, is the way the balance of payments works: it must balance.
What is more, because the current account surplus is by definition equal to the excess of Japanese savings over Japanese investment, the gap would have to narrow by an amount exactly equal to PBoC purchases. Here is where the exorbitant privilege collapses. If Japan needs foreign capital because it has many productive investments at home that it cannot finance for lack of access to savings, it would welcome Chinese purchases. PBoC purchases of yen bonds would indirectly cause productive Japanese investment to rise by exactly the amount of the PBoC purchase, and because the current account surplus is equal to the excess of savings over investment, the reduction in Japan’s current account surplus would occur in the form of higher productive investment at home. Both China and Japan would be better off in that case.But like other advanced economies Japan does not need foreign capital to fund productive domestic investment projects. These can easily be funded anyway. In that case PBoC purchases of yen bonds must cause Japanese savings to decline, so that its current account surplus can decline (if the gap between savings and investment must decline, and investment does not rise, then savings must decline). There are only two ways Japanese savings can decline: first, the Japanese debt burden can rise, which Tokyo clearly doesn’t want, and second, Japanese unemployment can rise, which Tokyo even more clearly doesn’t want.
There is no way, in short, that Japan can benefit from PBoC purchases of its yen bonds, which is why Japan has always opposed substantial purchases by foreign central banks. It is why European countries also strongly opposed the same thing before the euro was created, and it is why China restricts foreign inflows, except in the past year when it has been overwhelmed by capital outflows. The US and, to a lesser extent, the UK, are the only countries that permit unlimited purchases of their government bonds by foreign central banks, but the calculus is no different.
It turns out that foreign investment is only good for an economy if it brings needed technological or managerial innovation, or if the recipient country has productive investment needs that cannot otherwise be funded. If neither of these two conditions hold, foreign investment must always lead either to a higher debt burden or to higher unemployment. Put differently, foreign investment must result in some combination of only three things: higher productive investment, a higher debt burden, or higher unemployment, and if it does not cause a rise in productive investment, it must cause one of the other two.
The two conditions under which foreign investment is positive for the economy – i.e. it leads to higher productive investment – are conditions that characterize developing economies only, and not advanced countries like Japan and the US. These conditions also do not characterize developing countries that have forced up their domestic savings rates to levels that exceed domestic investment, like China.
