国际货币体系、债务的货币计价与过度特权

International Monetary System,the Currency Denomination of Debt and the Exorbitant Privilege

本文通过一个两国模型来理解国际货币在跨国金融交易中的计价作用。研究表明,在一个两国货币完全不对等的国际货币体系中(即只有其中一国的主权货币能够在国际金融市场上用于计价):当债务上限较低时,该国能够获得仅由货币计价产生的过度特权,这种特权并不依赖于该国在国际金融市场上的垄断定价能力,也不取决于该国货币作为贸易结算工具与作为安全资产之间的互补性;当债务上限提高到一定程度时,过度特权的存在则依赖于垄断定价能力。本文的结论,对于一国主权货币发展成为国际货币的路径选择,具有重要启示意义。

This paper constructs a two-country model to understand the denomination role of international currencies in cross-border financial transactions.In order to understand the role of international currency purely as a denominated currency,this paper analyzes two types of international monetary systems.The first system is complete equal,that is,the currencies of the two countries are both international currencies,and both can issue bonds denominated in their own national currencies in the international market.The second system is completely unequal,where only one international currency,and the two countries can only issue bonds denominated in the international currency in the international market.In order to differentiate the equilibrium of the two types of international monetary systems by monetary factors,this paper imposes a symmetry setting on the economic fundamentals of the two countries.This paper introduces bond issuance constraints,thus avoiding the external constraint that the two countries can only issue bonds denominated in their own national currencies.When the currencies of the two countries in the international monetary system are completely equal,this paper shows that in equilibrium,both countries issue bonds denominated in their own currencies and purchase bonds issued by the other country,which shows a cross-holding equilibrium of bonds between the two countries.This is consistent with the conclusion of the classic international macroeconomic literature.Although both currencies are international currencies,the price of exports is determined by the local currency pricing,so changes in the import demand of either country will affect the import expenditure of that country and also affect the foreign exchange income of the other country,making both countries bear the exchange rate risk at the same time.Therefore,hedging the exchange rate risk arising from the uncertainty of future import and export demand creates an incentive for bond cross-holding between the two countries.For example,when a country's export income decreases as a result of another country's declining future import demand,its holdings of another country's bonds can then maintain the purchasing power of future imports.Of course,if the future import and export demands are certain,then the import and export prices can be determined in advance,and there will be no exchange rate risk,the incentive for bond cross-holding between the two countries will disappear.The conclusion of the model in this paper implies that in a complete equal international monetary system,the bond cross-holding in equilibrium is equivalent to each country issuing its own currency in the international market and using it to buy other countries'currencies,then each country's central bank will hold other countries'currencies to form foreign exchange reserves.When the currencies of the two countries in the international monetary system are completely unequal,the results of this paper show that in equilibrium,the country of the international currency issues bonds denominated in international currency,and the other country buys bonds in the international market,and there is no equilibrium of bond cross-holding.Meanwhile,the international currency appreciates in the current period and the financing cost of the country's bonds is lower than that of the non-international curency country,namely the so-called exorbitant privilege,which is formed only from the denomination role of the international currency.For non-international currency country,since financial transactions in the international financial market can only be denominated in international currencies,it will inevitably bear exchange rate risks whether it issues or buys bonds denominated in international currencies.The research in this paper also indicates that in such an unequal international monetary system,the exorbitant privileges of the international currency country will disappear when its debt reaches a certain level,i.e.,such privileges do not exist without constraint.The paper further extends the model to the scenario of endogenous bond issuance constraints and a more general status of the two currencies,and then demonstrates that the so-called exorbitant privilege can still be obtained by international currency country.The conclusions of this paper have important policy implications for the path selection of a country's sovereign currency development into an international currency.