The bulk of （most of）international trade is done in the general mode of buying and selling of goods and services by means of money and the market. Under specific conditions, however, special modes of transactions may be adopted (used) to better realize one’s business purposes. Among them, counter trade and its variants (different forms) are perhaps the most popular modes of trade.Counter trade is a peculiar form of transaction allegedly (据说) popular in less developed countries and in centrally planned economies（中央计划型经济）. It has become the generic term to describe a set of cross-border contracts that link a seller’s exports to imports from the buyer, and it is often associated with policy objectives of relevant economies like dealing with foreign exchange shortages and promotion of exports（扩大出口）.MethodologyMathematicsphotographThe terminology counter trade employed (used) today can be traced to(date back) the pre-World War II years when normal trade relationswere breaking down (Great Depression). Following German hyperinflation，competitive devaluations (竞争性贬值)and protectionism meant a global collapse in trade and in international financial and banking markets. Unwilling to see Germany cut off from its traditional raw material supplies in the Balkans（巴尔干地区）, the Reichsbank agreed to the establishment of a clearing system （清算系统）that settled（结算）only net positions （实际头寸）- and only once a year - a measure that permitted traditional trade flowsbetween Germany and the Balkans to continue. These arrangements were called compensation trade. Another term used in the context of such bilateral clearing operations was “counter trade”. During and after World War II, when financial markets were in disarray（in disorder）, Britain used similar bilateral arrangements, as did Western Europe when setting up the European Payment Union. Subsequently (later) the countries of centrally planned economies copied such clearing systems and used them among themselves and also in tradewith neighboring countries like Finland. Conceptually, all these arrangements are trade credit accounts (贸易信贷往来账户) between familiar trading partners exchanging unrelated goods.In the 1970s and 1980s counter trade was different from the old practice although some similarities（likeliness）remained. Current counter trade partners are not necessarily familiar partners and goods exchanged are sometimes vertically related. Current counter trade can be categorized as follows: Barter(易货贸易): The directexchange of goods and services which is completed in a short period of time, e. g., an exchange of frozen lamb from New Zealand for Iran crude oil.Counter purchase（互购贸易；反向购买）: The assumption（assume 承担）by an exporter of a transferable obligation through separate but linked contract to accept as full or partial payment goods and services from the importer or importing country. The contract is usually stipulated to be fulfilled within a given period of time, e. g. , 5 years, and the goods or servicesreceived in return are usually pre-specified in a list and are subject to availability and changes made by the original importing country. In essence, then, counter purchase is an inter-temporal direct exchange of goods and services. For example, in 1977 V olkswagen sold 10,000 cars to the former East Germany and agreed to purchase goods from a list set up by the importer over the next 2 years, up to the value of the cars sold to the former East Germany.Buyback:（回购）An agreement by an exporter of plant and equipment（成套装置和设备）to take back in the future part of the output（产品）produced by these goods as full or partial payment. The important difference between counter purchase and buyback is that in buyback the goods and services taken back（buy back）are tied to (捆绑) the original goods exported whereas that is not the case in counter purchase. Another important difference is that a buyback deal usually stretches over (cover; extend 延伸) a longer period of time (as long as 15 to 20 years) than a counter purchase deal. For instance, the Xerox Corporation sold to Chinathe plant and technology for the production of low-volume photocopying machines, and contractually committed to repurchase a very large portion of the photocopy machines produced in the Chinese plant.The intriguing (interesting) features common to barter, counter purchase, and buyback is “bundling (捆绑)”: the exchanges of good s and services are bundled together (the exchanges are implemented either concurrently同时or inter-temporally不同时). In normal market transaction buying andselling of goods and services is unbundled (不捆绑), an arrangement made possible by the use of money and the “market” as an institution （手段）. Thus, an individual can sell goods and services to obtain monetary income and can then use the income for other desired goods and services. Such unbundling greatly facilitates（便利；促进）transaction and allows more efficient economic exchanges.While counter trade does not represent an extreme form of bundling, and money as a unit of account（记账单位）is not totallybypassed - in many counter trade deals, only a fraction of (a small part of) the initial (最初的) purchase is paid for in goods and services - the question remains why a significant （quite big）part of the buying and selling of goods and services should be bundled together.The impression one gets is that bundled trade takes place where the market institution(system) is imperfect. It can be said to generally take place between mature market economies and economies with a less sophisticated（mature）market system. Under such circumstancethere are several presumed (被公认的) advantages in counter trade:1.Counter trade is implemented (carry out) because it helps a country to deal with foreign exchange shortages.2.Counter trade can be used to promote exports.3.Counter trade can be used to reduce uncertainty regarding export receipts. (income, earnings)4.Counter trade is used to bypas s (避开) an international price agreement like, for example, that of OPEC （cartel）.5.Counter trade may help thosenations with serious debt problems （debtor nation 债务国）to continue to import goods while, in effect, conceal ing (隐瞒) export earnings from creditors (债权人).However, counter trade can be very risky business. By conceal ing the real prices and costs of transactions it may conceal and help perpetuate（使永久存在）economic inefficiencies in the market place. Companies may suffer losses because they could not get rid of （sell）products of poor quality. Finally, counter trade may be considered as a form ofprotectionism.Among other modes of trade are processing trade, consignment, leasing trade, agency etc.。