利用者:ShuBraque/sandbox/最適通貨圏

国際的リスク共有のもとでの最適通貨圏の理論

Mundell's work can be cited on both sides of the debate about the euro. Most economists cite preferentially the first (stationary expectations) model, and conclude against the optimality of the euro. However, in 1973 Mundell himself constructed an argument on the basis of the second model that was more favorable to the concept of a (then-hypothetical) shared European currency.

Rather than moving toward more flexibility in exchange rates within Europe the economic arguments suggest less flexibility and a closer integration of capital markets. These economic arguments are supported by social arguments as well. On every occasion when a social disturbance leads to the threat of a strike, and the strike to an increase in wages unjustified by increases in productivity and thence to devaluation, the national currency becomes threatened. Long-run costs for the nation as a whole are bartered away by governments for what they presume to be short-run political benefits. If instead, the European currencies were bound together disturbances in the country would be cushioned, with the shock weakened by capital movements. — Robert Mundell, 1973、A Plan for a European Currency pp. 147 and 150

oldid=652878239 を追加訳出　さらに多少の改訳

OCA with international risk sharing

Here Mundell tries to model how exchange rate uncertainty will interfere with the economy; this model is less often cited (publication in 1973).

Supposing that the currency is managed properly, the larger the area, the better. In contrast with the previous model, asymmetric shocks are not considered to undermine the common currency because of the existence of the common currency. This spreads the shocks in the area because all regions share claims on each other in the same currency and can use them for dampening the shock, while in a flexible exchange rate regime, the cost will be concentrated on the individual regions, since the devaluation will reduce its buying power. So despite a less fine tuned monetary policy the real economy should do better.

A harvest failure, strikes, or war, in one of the countries causes a loss of real income, but the use of a common currency (or foreign exchange reserves) allows the country to run down its currency holdings and cushion the impact of the loss, drawing on the resources of the other country until the cost of the adjustment has been efficiently spread over the future. If, on the other hand, the two countries use separate monies with flexible exchange rates, the whole loss has to be borne alone; the common currency cannot serve as a shock absorber for the nation as a whole except insofar as the dumping of inconvertible currencies on foreign markets attracts a speculative capital inflow in favor of the depreciating currency.

—Mundell, 1973、Uncommon Arguments for Common Currencies p. 115

Mundell's work can be cited on both sides of the debate about the euro. Most economists cite preferentially the first (stationary expectations) model, and conclude against the optimality of the euro. However, in 1973 Mundell himself constructed an argument on the basis of the second model that was more favorable to the concept of a (then-hypothetical) shared European currency.

Rather than moving toward more flexibility in exchange rates within Europe the economic arguments suggest less flexibility and a closer integration of capital markets. These economic arguments are supported by social arguments as well. On every occasion when a social disturbance leads to the threat of a strike, and the strike to an increase in wages unjustified by increases in productivity and thence to devaluation, the national currency becomes threatened. Long-run costs for the nation as a whole are bartered away by governments for what they presume to be short-run political benefits. If instead, the European currencies were bound together disturbances in the country would be cushioned, with the shock weakened by capital movements.

—Robert Mundell, 1973、A Plan for a European Currency pp. 147 and 150

Criticism

Keynesian

The notion of a currency that does not accord with a state, specifically one larger than a state – formally, of an international monetary authority without a corresponding fiscal authority – has been criticized by Keynesian and Post-Keynesian economists, who emphasize the role of deficit spending by a government (formally, fiscal authority) in the running of an economy, and consider using an international currency without fiscal authority to be a loss of "monetary sovereignty".

Specifically, Keynesian economists argue that fiscal stimulus in the form of deficit spending is the most powerful method of fighting unemployment during a liquidity trap. Such stimulus may not be possible if states in a monetary union are not allowed to run sufficient deficits. The Post-Keynesian theory of Neo-Chartalism holds that government deficit spending creates money, that ability to print money is fundamental to a state's ability to command resources, and that "money and monetary policy are intricately linked to political sovereignty and fiscal authority". Both of these critiques consider the transactional benefits of a shared currency to be minor compared to these drawbacks, and more generally place less emphasis on the transactional function of money (a medium of exchange) and greater emphasis on its use as a unit of account.

Austrian

→詳細は「Free banking」を参照

Offering a contrary criticism, Austrian economists have supported the disassociation of currencies from political entities entirely. Whereas Keynesians see flaws in supranational currencies, Austrians see flaws in any centrally planned currency not determined by a free market process. This alternative approach seeks to limit deficit spending, as well as to increase the accountability of currency makers to their users in the same way that markets for other goods maximize the accountability of businesses to their customers. Founding Austrian economist Friedrich Hayek advocated denationalization of money reasoning that private enterprises which issued distinct currencies would have an incentive to maintain their currency’s purchasing power and that customers could choose from among competing offerings. Thus, the Austrian critique of optimal currency areas does not prejudice any particular arrangement so long as it is arrived at by a fair and competitive market process. From "The Failure of OCA Analysis" (The Quarterly Journal of Austrian Economics):

Monetary unification enhances the welfare of individuals only if it springs naturally from the voluntary actions of the money users...In a free market, entrepreneurs will try to respond properly to the demands of their customers, providing goods—including money—of the type, quantity, and quality desired. Therefore, only in a free monetary market would it be possible to discover what is the “optimum” circulation of a certain currency...OCA theory fails to acknowledge this, precisely because it conflates the proper nature of money, focusing exclusively on a single type of money, namely fiat government-produced money.

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See also

• Mundell–Fleming model