Chapter 3
Methodology

Alternative approaches

3.2Several alternative approaches to determining offence seriousness and setting maxima were considered and rejected.

3.3First, we considered the measure of offence seriousness developed by the Ministry of Justice in 1991.13
3.4Under this system, the seriousness of an offence is measured by the average number of days of imprisonment imposed on each offender convicted for that offence over a five year period. The average figure covers both imprisoned and non-imprisoned offenders. For example:14

Between 1995 and 1999 there were 100 cases of offenders convicted of a particular offence. Of these cases, 50 resulted in a custodial sentence, and the average length of the custodial sentences imposed on these offenders was 30 days. The seriousness score for this offence is (30 x 50/100), or 15.

3.5This model is not suitable for this review. Not only does it limit the determination of offence seriousness to sentencing data (thereby accepting the correctness of the status quo and ignoring other criteria), but it produces an index of offence seriousness based on average sentences of imprisonment. By contrast, this review will be based on the worst class of case for each offence. So the average number of days of imprisonment (30 days in the above example) includes the whole spectrum of custodial sentences handed down for an offence, rather than focusing on sentences imposed at the top end.

3.6Secondly, we examined the 1978 United Kingdom Advisory Council review of maximum penalties which proposed a more radical approach.15 The Council recommended that maxima for each offence be set so as to capture 90 per cent of the sentences currently imposed for each offence. Put differently, the maxima would be set lower than the highest 10 per cent of sentences handed down.16 This still suffers from the problem that it is based on current sentencing practice. In addition, it is subject to the major criticism that, in recommending maxima that could not capture the worst class of case, the Council effectively abandoned the rationale underpinning statutory maxima.17 Because we take the view that maximum penalties should be based on the seriousness of the worst class of case, we rejected this model.

3.7Nevertheless, we are conscious that our own model has limitations. Inevitably, regardless of the method used, the ranking of offences according to seriousness inevitably involves a degree of subjectivity and personal value judgement. Reasonable people using the same guiding principles will inevitably disagree about which offences are more serious than others. For that reason, we have not focused on the minor discrepancies between the offence groupings that our methodology produced and current maximum penalties. Rather, we have highlighted and discussed substantial discrepancies that in our view clearly indicate that appropriate relativities between offences are not properly reflected in current law.

3.8In the remainder of this chapter we consider the first two steps in our process (those directed towards the development of an appropriate quantitative tool for measuring harm) in more detail.

13Phillip Spier Conviction and Sentencing of Offenders in New Zealand 1991–2001 (Ministry of Justice, 2001) at 11–13.
14At 11.
15Advisory Council on the Penal System Sentences of Imprisonment: A Review of Maximum Penalties (HMSO, London, 1978).
16Judges would have been able to exceed the maximum in exceptional cases (ie the estimated 10 per cent of cases that warranted a sentence above the new maximum) and would in that event have not been subject to any maximum.
17One critic suggested “…the Council’s proposal amounts to an abolition of maximum penalties altogether. The new maxima would not be maxima at all; rather, they would amount to an efficiency bar on an unlimited incremental scale”: DA Thomas “Report of Committees, Sentences of Imprisonment – a Review of Maximum Penalties” (1979) 42 MLR 309 at 311.