什麼是市場

某種工具，可以使買方和賣方相互進入，以達成契約交換財貨及服務。市場一詞，原本指涉產品買賣的一處具體地方；現在市場一詞則指涉任何場合，不論是多麼抽象或多麼遙遠，只要能夠促成買賣雙方完成交易即可算數。例如倫敦和紐約的商品交易所（commodity exchanges），就是交易員透過電話、電腦連線及直接喊價而構成的跨國性市場。市場交易的標的物，不只包括看得到摸得着的商品，例如穀物和牲畜，也包括抽象的金融商品，例如證券（securities）和貨幣（currencies）。古典經濟學致力於發展「完全競爭」的理論，他們設想的自由市場，是一處大批買方和賣方能輕易溝通及交易商品的地方；在這樣的市場中，價格完全由供給和需求（supply and demand）所決定。但在1930年代以後，經濟學家的關注點已轉移到「不完全競爭」，認爲供給和需求並不是影響市場運作的僅有因素。在不完全競爭中，買方和賣方的數量是受到限制的，競爭產品是相互區隔分化的（透過不同的設計、品質和品牌），而且會設下障礙來阻擋新進者加入市場。

market

Means by which buyers and sellers are brought into contact with each other and goods and services are exchanged. The term originally referred to a place where products were bought and sold; today a market is any arena, however abstract or far-reaching, in which buyers and sellers make transactions. The commodity exchanges in London and New York, for example, are international markets in which dealers communicate by telephone and computer links as well as through direct contact. Markets trade not only in tangible commodities such as grain and livestock but also in financial instruments such as securities and currencies. Classical economists developed the theory of perfect competition, in which they imagined free markets as places where large numbers of buyers and sellers communicated easily with each other and traded in commodities that were readily transferable; prices in such markets were determined only by supply and demand. Since the 1930s, economists have focused more often on the theory of imperfect competition, in which supply and demand are not the only factors that influence the operations of the market. In imperfect competition the number of sellers or buyers is limited, rival products are differentiated (by design, quality, brand name, etc.), and various obstacles hinder new producers' entry into the market.