Although the idea that the judiciary should be independent is relatively new and the mixing of judicial, legislative and executive duties commonplace for most of history, an independent judiciary is now seen both as a salient feature of a government under the rule of law and as the core of many constitutional arrangements in most developed countries as well as in the legal literature.

A number of constitutional and legal writings by political philosophers and constitutional lawyers, including John Locke, Charles-Louis de Secondat Montesquieu, James Madison and Thomas Jefferson have defined judicial independence as an essential aspect of the separation of powers, central to the conception of the judiciary as the third branch of government.

Threats to judicial independence are issued not only by the political branches of government but also by the particular interests at work in the judicial process. Judicial independence therefore also includes freedom from any external pressure, such as freedom from economic factors (judges must be free from having their financial well-being depend on the outcome of the cases they hear) and freedom from physical compulsion (judges cannot be coerced into rendering particular decisions). Thus, in accordance with the most basic precepts of due process, independence from private interests prevents a judge from being a judge in his/her own case. It also provides specific disqualification standards requiring judges to decline to give an opinion whenever they have pecuniary interest in a case. In addition, in reference to the notion of impartiality, the principle of judicial independence makes it necessary to sanction bribes and corruption situations that would make the pecuniary well-being of a judge directly dependent on the sense of the decision.

Consistently with the standard rationality and self-interest assumptions, the economic literature develops an analysis of judicial independence that is mostly based on the examination of the goals and motivations of agents. It points out both the political and litigation dimensions of the principle. This chapter will first present the variety of institutional arrangements aimed at organizing judicial independence and their various outcomes. Second, judi­cial independence from the political decision makers will be analysed through the lens of the economic analyses in both normative and positive dimensions. Independence from the litigants will then be discussed in relation to the rent­seeking problem. Finally, concluding comments will briefly present some controversies that shape the debate around judicial independence, in relation to the judicial accountability debate and the influence of peers on judicial decision making.