Application of rules is the least interesting part of judicial decision making. Vastly more intellectually absorbing is the process of reaching a decision by balancing of conflicting rights, values or interests.
"... balancing introduces order into legal thought. It requires the judge to identify the relevant values; it requires the judge to address the problem of the relative social importance; it requires judges to reveal their way of thinking to themselves, as well as to others. It facilitates self-criticism and criticism from the outside. As Judge Coffin wrote:
"Open balancing restrains the judge and minimises hidden or improper personal preference by revealing every step in the thought process; it maximises the possibility of attaining collegial consensus by responding to every relevant concern of disagreeing colleagues; and it offers a full account of the decision-making process for subsequent professional assessment and public appraisal. [See Frank M Coffin, "Judicial Balancing: The Protean Scales of Justice," 63 NYULRev 16, 25 (1988).]
" Indeed, balancing is a way of thinking; it is a conceptual mentality; it is a process that leads to decision. It requires dealing with how genuinely problematic is the situation created by conflicting values. [See Frank Michelman, "The Supreme Court 1985 Term – Foreward: Traces of Self Government," 100 Harv L Rev 4, 34 (1986).]"
Aharon Barak, The Judge in a Democracy (2006), p 173.
Relatively simple balancing can occur where one person's interest is weighed against another's. An example is the determination of whether the actus reus of disorderly behaviour includes the act of singing outside the complainant's house, on the street, in daytime, and intentionally causing the complainant, a night shift worker, to lose sleep: Brooker v R 4 May 2007. Balancing here was controversial: two judges applied balancing and two applied rights limitation; see further my note dated 4 May 2007. Balancing also occurs where the issue is media access to court proceedings: Rogers v TVNZ 19 November 2007.
A more orthodox environment for balancing is the decision whether evidence should be ruled inadmissible because it was obtained improperly. A case may require two balancing exercises: one to determine whether there had been an impropriety in the obtaining of the evidence, and, if there had, the other to determine whether that evidence is admissible: R v Singh 2 November 2007.
The exercise of anticipating the result of an admissibility decision can be approached by lawyers in different ways: by studying how judges have arrived at such decisions, or by studying the results of those decisions and identifying the pattern of precedents. A statute may tell judges what factors to take into account, and what the criterion for decision is (for example, whether exclusion of the evidence is proportionate to the impropriety (s 30(2)(b) Evidence Act 2006[NZ]). Anticipating the weight that will be given to each factor and where the balance will rest is not easy without reference to precedent, and for this reason lawyers may more easily focus on the results in similar cases.
The Supreme Court of Canada has offered an explanation of the way judges should reach their decisions in balancing cases involving improperly obtained evidence: R v Grant 18 July 2009, and has illustrated it in R v Harrison 19 July 2009. The conceptual model of the decision was described by the Chief Justice as a "decision tree". It has difficulties which are reflected in its three-dimensional structure. In New Zealand there has been a transition from the pre-Bill of Rights Act 1990 spectrum model to a period of rule application during the early days of the Bill of Rights, to a discretionary approach now enacted as the abovementioned s 30 Evidence Act 2006. The current balancing is two dimensional and precedents can easily be placed on a diagram which makes predictions of results a relatively simple task. At least, it's a simple task for people who are not afraid of diagrams.
Another form of judicial balancing occurs where a decision has to be made about whether the probative value of evidence is outweighed by the risk that the evidence will have an unfairly prejudicial effect on the proceeding. This balancing is familiar throughout the jurisdictions that have laws of evidence (not including, for example, the civil law countries of continental Europe, although a similar balancing is seen in Germany: Gafgen v Germany 3 July 2008). It is not an easy weighing exercise on which to construct a conceptual model as in each case the judge's perception of the risk of prejudice is very much a personal matter. There was unanimity that certain evidence should be excluded under this weighing exercise in the New Zealand Supreme Court in Bain v R 12 June 2009, but, before the case got to the five judges of that court, four judges had held the disputed evidence admissible. It is arguable that this weighing exercise is misconceived because it leaves room for significant risk of prejudice if the probative value is assessed as high. The decision could better be put as whether admission of the evidence would create an unacceptable risk of unfairness. That would avoid weighing altogether.