【正确答案】 1、(1) In a non-fixed exchange rate system, reserves allow a central bank to purchase the issued currency, exchanging its assets to reduce its liability. The purpose of reserves is to allow central banks an additional means to stabilize the issued currency from excessive volatility, and protect the monetary system from shock, such as from currency traders engaged in flipping. Large reserves are often seen as strength, as it indicates the backing a currency has. Low or falling reserves may be indicative of an imminent bank run on the currency or default, such as in a currency crisis. Central banks sometimes claim that holding large reserves is a security measure. This is true to the extent that a central bank can prop up its own currency by spending reserves. (This practice is essentially large-scale manipulation of the global currency market. Central banks have sometimes attempted this in the years since the 1971 collapse of the Bretton Woods system. A few times, multiple central banks have cooperated to attempt to manipulate exchange rates. It is unclear just how effective the practice is. ) But often, very large reserves are not a hedge against inflation but rather a direct consequence of the opposite policy; the bank has purchased large amounts of foreign currency in order to keep its own currency relatively cheap. 　　(2) A country's foreign exchange reserves consist of the financial assets under the control of the monetary authority that are readily available for balance of payments financing. While the definition of reserves is straightforward, measuring them is more complicated because of the need to account for future claims on reserves, for example, from derivative contracts. 　　(3) The ideal solution would be to net out those claims on reserves that might result in immediate drains on reserves and other elements that might overstate gross reserves, yielding a concept of "usable reserves". To help implement this concept, the IMF developed in 1999 a template for reporting reserves, which is now being used by about 50 countries, including 30 emerging market countries. However, data on usable reserves are only available for a very limited period, so this essay focuses on gross foreign reserve assets net of gold. The main reason why countries hold foreign exchange reserves is to smooth unpredictable and temporary imbalances in international payments. Thus, the basic idea in the theory of the demand for reserves is that a country chooses a level of reserves to balance the macroeconomic adjustment costs incurred if reserves are exhausted (the precautionary motive) with the opportunity cost of holding reserves. Building on this theory, empirical work has identified a relatively stable long-run demand for reserves that is based on a limited set of explanatory variables.