This paper tries to clarify some mis- understandings and prejudice against liberalism by analyzing the concepts of justice, liberty, equality and efficiency.

Okun makes value analysis and judgement on the problems of relation and tradeoff between equality and efficiency by a visual angle of overstepping economic field, and thus forms the unique tradeoff theory: taking “the unity of pluralism as its foundation, “giving priority to efficiency and promoting equality” as its method, “proper intervention measures of government” as its mechanism.