The development of administrative tribunals in many countries is associated with the increased powers of the State which the growing complexity of society and demands for social justice have caused. In New Zealand the State has long exercised functions that elsewhere were until recently, or still are, in private hands. It might be expected, therefore, that administrative tribunals would have become important at an early period. This did not happen. One reason is that earlier State intervention commonly took the form of ownership or detailed administration. Only since 1936 has there been extensive Government regulation of the economy outside the public sector, and it is here that independent tribunals abound and play a particularly important role.
Administrative tribunals may be regarded as intermediate between Courts and the ordinary administration, possessing characteristics of each. Their membership, functions, and procedure vary greatly, although in New Zealand almost all possess the powers of a Commission of Inquiry. They have in common an identifiable membership, in contrast to the anonymity of administration, and the duty to act judicially, including the obligation to hear the parties. This duty also involves freedom from Government influence in deciding particular cases, although some tribunals must have regard to Government policy directives. On the other hand, the procedure of tribunals is less (often much less) formal than that of the Courts; they are not bound by the ordinary rules of evidence and their members almost always have less security of tenure than do Judges or Magistrates.
No a priori rules exist for determining whether a function will be given to an administrative tribunal. Broadly speaking, tribunals are established to demonstrate that cases affecting the citizen's rights will be fairly decided where the ordinary Courts are unsuitable to deal with the issues involved. In this country disputes about welfare benefits are decided administratively and not by independent tribunals, a policy the justice of which is arguable. The ordinary Public Service, however, also administers many controls affecting individual property rights–for example, import and exchange controls. Grounds commonly said to justify the handling of a particular subject-matter by a tribunal rather than by a Court are that there will be a great number of petty cases; that a wide discretion is involved, especially to decide what is fair and reasonable; that the field is technical and specialised, so that the ordinary Courts are inexpert; or that the element of social or economic policy is large. The first ground has had little application in New Zealand. Nor is the superiority of tribunals over Courts in exercising discretionary powers obvious in the light of our experience. The other grounds have more validity, and most tribunals in this country have been established for one of these reasons.