Market economy is essentially a contract economy, contract of the modern rule of society is one of the basic elements, it stipulates the interests of parties on the rights and obligations of two-way dependent Contracted spirit common explanation is honesty, its commitments to legal basis, thereby more reliable than moral Contracted spirit test a place oneself in social relations of each member, also includes the America's powerful have various reason, if from 390 years ago the history of the United States first political contractual documents - the mayflower convention to extricated can perhaps from system level find America's strongest root 市场经济本质上是契约经济,契约也是现代法治社会的基本构成要素之一,它规定着利益各方在权利与义务方面的双向依存关系。契约精神的通俗解释就是诚信,它的承诺以法制为基础,因而比道德约束更可靠。契约精神考验着置身于社会关系中的每位成员,也包括政府。美国的强大有各种理由,如果从390年前美国历史上的第一个政治契约性文件--《五月花号公约》中去探源,或许能够从制度层面找到美国强大的根本原因。