Of course it can help in understanding a statute to examine the social and economic facts which led to its passing, and the social and economic context in which it must now operate. Sometimes that context is general knowledge. But some statutes are of a more specialist kind where the context in which they must operate requires evidence and explanation to sharpen our understanding. I refer, for example, to the Commerce Act 1986. A proper understanding of the concepts in that Act can only be obtained after the reading of much literature, both national and international. The same is true of the Resource Management Act 1991. You cannot read an Act like that in a vacuum. SIR IVOR has been one Judge who has openly advocated the presentation to the court of contextual material in cases like this.
The desirability of this goes without saying. Better-informed decisions are likely to be more correct decisions. Yet it would be idle to ignore the difficulties. Too much material can confuse, and undesirably lengthen court proceedings. An even greater danger can lie in members of one profession trying to acquire expertise in another. To inform a court properly of the social and economic background to a specialist piece of legislation can require much time, skill and knowledge on the part of the advocate. And there is always the danger that if the advocate is outside his or her own area of expertise the information presented may be partial or even inaccurate. The difficulties of venturing into unfamiliar territory occasionally receive interesting expression in the Privy Council. There have been occasions where their Lordships, rather than entering into a thorough examination of New Zealand history and context, have preferred to decide a case by old-fashioned reliance on the dictionary meaning of the words in the statute itself. There is, I think, simply no answer to this paradox. Contextual material is desirable; to acquire it fully and accurately may be very difficult indeed. Similar difficulties beset the interpretation of contracts in specialist areas such as the construction industry. To become thoroughly acquainted with trade practice and "the matrix of fact" surrounding such contracts is a formidable task.
Secondly, there has been a revolution in the admission of Parliamentary material. Once it was totally excluded. Now it is regularly admitted.
Over the past 15 years or so in New Zealand, and more recently in England, it has become a common occurrence for counsel to cite, and courts to refer to, extracts from Parliamentary debates, explanatory notes to Bills, amendments to Bills, and, more recently, reports of select committees. Most commonly they are used to provide contextual background and evidence of the genesis of the Bill in question. But sometimes our courts are using them for statements by the policy makers as to the purpose of a piece of legislation and the intent behind it, and sometimes even for evidence of a specific intention about the problem before the court. In the not-so-distant past that would have been regarded as unthinkable.
No doubt time is sometimes wasted by reference to proceedings that turn out to be unhelpful. Indeed a member of the House of Lords has stigmatised the newfound power as an expensive luxury, and there has been a recent attempt by the House of Lords to confine its use. One also has to be alive to the dangers of a Minister, or an official, "planting" statements with the intention that they should influence interpretation. And particular care must be taken to ensure that statements of policy made early in the process remain reliable after amendments to the Bill in select committee or at committee of the whole stage; in the new MMP environment that risk is greater than ever before. However, quite often reference to Parliamentary materials does produce something of value. Occasionally judges expressly acknowledge how helpful they have found, say, a statement by a Minister in the House. Overall, the ability to have resort to Hansard has been much more productive than the pessimists predicted.
But it is important not to misconstrue what is going on here. The statements found in these documents are not the word of Parliament. Parliament's authority attaches only to the words of the legislation that it passes. It is therefore not really true to say, as sometimes is said, that one is using these Parliamentary documents as direct evidence of the intention of Parliament. But it is clearly relevant and helpful to know what the proponents of a Bill or clause, normally but not always the government, and those responsible for drafting it, intended to achieve by it. The intentions and purposes of those most directly responsible for the legislation cannot be dismissed as having no value. There is no reason why the courts should not use their statements as a tiebreaker in a case of real ambiguity, or to add persuasive force to an interpretation to which the court is tending for a variety of reasons. (Indeed quite often decisions on statutory interpretation are arrived at by a number of separate arguments using language, scheme, purpose, history and perhaps statements in Hansard.)
However the courts might be said to have the best of both worlds. Since the statements in Hansard are not endorsed by Parliament, they are not binding and therefore do not have to be followed. It is perfectly legitimate for the court to decline to follow what a Minister has said in the House. It has happened. It is open to a court to say that a Minister has misunderstood the law; or that the debates are confused and reveal shifts in stance by the government itself; or (even) that they suggest that members failed to appreciate the significance of what they were about to enact. In other words, statements in these Parliamentary materials can be used in rather the way that judicial dicta and academic commentary have been used over the years: to give weight to a particular argument but to be rejected if felt to be unhelpful. They are used to assist rather than to constrain. In LORD WILBERFORCE’s terms, they do not turn the court into "a reflecting mirror of what some other agency might say". They are an important accessory to the purposive style of interpretation.
 Rt Hon Sir Ivor Richardson "The Role of Judges as Policy Makers" (1985) 15 VUWLR 46, 51-52; Williams v Attorney-General  1 NZLR 646, 681 (CA) Richardson J
 For example, New Zealand Apple and Pear Marketing Board v Apple Fields Ltd  1 NZLR 257, 262 (CA) Richardson J: “Their Lordships fully recognise the great importance which the Judicial Committee of the Privy Council should always attach to the opinion of Judges exercising jurisdiction in a Commonwealth country in any matter which may reflect their knowledge of local conditions. Yet, when an issue is wholly governed by statute, its resolution must be purely a matter of interpretation.”
 Lord Steyn "Pepper v Hart; A Re-examination" (2001) 21 Ox J Leg Stud 59
 R v Secretary of State for the Environment, ex parte Spath Holme Ltd  2 AC 349 (HL)
 See for example De Richaumont Investment Co Ltd v OTW Advertising Ltd  2 NZLR 831, 841 (HC) Priestley J; Everitt v Attorney-General  1 NZLR 82, 95 (CA) Richardson P.
 R v Bolton (1986) 79 ALR 225 (HC); McLennan v Attorney-General  2 NZLR 469 (CA), See also R v Poumako  2 NZLR 695, 702 (CA) Richardson P
Te Runanga o Ngai Tahu v Waitangi Tribunal  3 NZLR 87, 102-103 (CA) Richardson P
R v Pora  2 NZLR 37, 49 (CA) Richardson P