Currency Unions

每个国家都应该有自己的货币吗？每个国家应该有且只有一种货币流通吗？世界上应该流通多少种货币：1种、10种、50种，还是目前大约180种？由于过去几十年的政治经济发展，独立国家的数量大幅增加，这些问题成为政策辩论的首要问题。1947年，世界上有76个国家；今天有193个，几乎没有例外，所有这些国家都有自己的货币。除非有人认为一个国家在定义上是一个最优货币区，否则在1946年货币太少，或者今天货币太多。事实上，考虑到国与国之间贸易和金融一体化(所谓的全球化)的显著增长，人们可能会认为，在后11次世界大战期间，货币的数量将减少而不是增加。货币联盟面临的另一个压力来自重新强调价格稳定，而不是积极的宏观经济稳定，作为货币政策的主要目标。这种政策立场的改变很可能是对上世纪七八十年代通货膨胀的反应。由于这些发展，“一国/一种货币”这一毋庸置疑的身份正日益受到质疑。这个项目从理论和经验上研究什么是“世界上最理想的货币数量”的问题。基本策略是将新的经济分析与现有的两种文献相结合。其中之一是关于替代汇率制度和最优货币区的研究；第二是关于政治司法管辖区形成和国家均衡数量的文献。最初的理论研究表明，货币联盟的好处如何取决于交易成本、承诺能力、价格和产出的共同变动、锚定国对客户的通融以及铸币税收入的处理。进一步的研究表明，地理因素如何决定货币联盟的均衡配置。进一步的研究包括对理论框架中一些关键关系的经验估计、对商品和金融服务交换中的本土偏向的来源的评估、对与货币安排共同确定的国家规模的处理、对货币联盟和金融发展之间相互作用的评估、对政策制定者的潜在承诺能力的分析，以及更明确地允许潜在的锚定货币之间的竞争。

Should each country have its own currency? Should one and only one currency circulate in each country? How many currencies should circulate in the world: 1, 10, 50, or the current number of roughly 180? These issues are at the forefront of the policy debate because of the politicoeconomic developments of the last few decades, which featured a large expansion of the number of independent countries. In 1947, there were 76 countries in the world; today there are 193 and, with few exceptions, all of these countries have their own currencies. Unless one believes that a country is by definition an optimal currency area, either there were too few currencies in 1946 or there are too many today. In fact, given the phenomenal increase in trade and financial integration between countries (the so-called globalization), one might have expected the number of currencies to decrease rather than increase in the post-World War 11 period. An additional pressure toward currency unions has come from the renewed emphasis on price stability, rather than active macroeconomic stabilization, as the main objective of monetary policy. This change in policy stance is likely a reaction to the inflationary decades of the seventies and eighties. As a result of these developments, the unquestioned identity "one-country/one-currency" is increasingly being called into question.This project studies, theoretically and empirically, the question of what is the "optimal number of currencies in the world." The basic strategy is to combine new economic analysis with two existing strands of the literature. One of these strands is the work on alternative exchange rate regimes and optimal currency areas; the second is the literature on formation of political jurisdictions and the equilibrium number of countries.The initial theoretical research shows how the benefits from currency union depend on trading costs, commitment abilities, co-movements of prices and outputs, accommodations of anchor countries to clients, and treatments of seignorage revenue. Further work shows how geographical considerations determine equilibrium configurations of currency unions. Further research includes empirical estimation of some of the key relationships in the theoretical framework, assessment of the sources of home bias in exchanges of goods and financial services, treatment of country size as jointly determined with currency arrangements, assessment of the interplay between currency union and financial development, analysis of underlying commitment abilities of policymakers, and more explicit allowance for competition among potential anchor currencies.