International Currencies and Capital Allocation

We establish that global portfolios are driven by an often neglected aspect: the currency of denomination of assets. Using a dataset of $27 trillion in security-level investment positions, we demonstrate that investor holdings are biased toward their own currencies to such an extent that each country holds the bulk of all foreign debt securities denominated in their own currency. Surprisingly, currency is such a strong predictor of the nationality of a security's holder that the nationality of the issuer - to date, the most powerful predictor in a voluminous literature on cross-border portfolios - adds very little explanatory power. While large firms issue bonds in foreign currency and borrow from foreigners, the vast majority of firms issue only in local currency and do not directly access foreign capital. These patterns hold across countries with the exception of the US, which issues an international currency. The global willingness to hold US dollars means that even smaller US firms that borrow exclusively in dollars have little difficulty borrowing from abroad. Global portfolios shifted sharply away from the euro and toward the dollar after the 2008 financial crisis, further cementing the dollar's international role and potentially amplifying the benefit its status brings to the US.