Currency Unions

每个国家都应该有自己的货币吗？每个国家应该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，这些问题处于政策辩论的前沿，其特点是独立国家的数量大量增加。1947年，世界上有76个国家；如今有193个国家，除了少数例外，所有这些国家都有自己的货币。除非有人认为，根据定义，一个国家是最优货币区，否则1946年的货币要么太少，要么今天的货币太多。事实上，考虑到国家间贸易和金融一体化（所谓的全球化）的显著增长，人们可能会预期，在第二次世界大战后的时期，货币的数量会减少而不是增加。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，这是货币政策的主要目标。这种政策立场的转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”这一不容置疑的特性正日益受到质疑。该项目从理论上和经验上研究了“世界上最优货币数量”的问题。基本策略是将新的经济分析与两种现有的文献结合起来。其中一个分支是关于替代性汇率制度和最优货币区的研究；第二部分是关于政治管辖的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、锚定国对客户的适应，以及对铸币税收入的处理。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实证估计，对商品和金融服务交换中本土偏见来源的评估，将国家规模视为与货币安排共同决定的，对货币联盟与金融发展之间相互作用的评估，对政策制定者潜在承诺能力的分析，以及对潜在锚定货币之间竞争的更明确的考虑。

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.