International comparisons of crime

The question ‘How do results from the New Zealand Crime and Safety Survey compare to surveys in other countries?’ is often asked. Unfortunately, comparing statistics collected in different surveys is not often possible. The reasons are explained below.

How to compare NZCASS statistics with other surveys

When looking at similar statistics between surveys, researchers ask themselves a range of questions including (but not limited to) those listed below. This is done to check that we are comparing ‘apples with apples’ and do not draw incorrect conclusions. In most cases when comparing surveys, a number of the questions below are answered ‘no’ and so direct comparisons of statistics are unadvisable. For this reason, we do not compare NZCASS statistics with other similar surveys.

	NZCASS	Question to ask
Sampling method	Nationwide, random probability survey, with respondents selected from households using multistage stratified cluster sampling methods.	Is the sampling method the same as the NZCASS?
Target population	Total usually resident, non-institutionalised, civilian population of New Zealand aged 15 years and over.	Is the target population the same as the NZCASS?
Interviewing period	10 February 2014 to 6 July 2014	Is the interviewing period the same or similar?
Recall period	1 January 2013 to date of interview	Is the recall period equivalent to the NZCASS?
Offence coverage	Please review our offence coding information to understand the range of household and personal offences included in the NZCASS.	Are the same offences covered and do those offences have the same definitions as in New Zealand?
Classifications & groupings	Surveys group offences in different ways to produce reporting statistics. Please review the classifications, groupings & standards used as part of the NZCASS.	Are the classifications or groupings that you are comparing the same?
Truncation	The number of offences that can be counted per person in the NZCASS is capped at 60.	Does the research you are comparing have the same truncation rules as the NZCASS?
Questions asked	In the NZCASS questions are asked about different things (incidents) that might have happened to the survey participant or their household. These incidents are then coded by legal experts to determine whether or not the incident was a crime, and what type of offence (or offences) happened. Please refer to the questionnaire to review the specific questions asked.	Are the questions asked to collect offence information the same as those asked in the NZCASS?

Common findings between the NZCASS and selected international surveys

While we can’t directly compare statistics between the NZCASS and similar international surveys, a number of common themes were found as part of a 2010 review of international research.

The NZCASS in an International Context: Comparing the New Zealand Crime and Safety Survey with other international victim surveys, December 2010 [PDF, 253 KB]

International Crime Victims Survey (ICVS)

One way to compare crime and victimisation between countries is by using the same survey. New Zealand took part in the International Crime Victims Survey (ICVS) in 1992. More information about this research can be found at unicri.it/services/library_documentation/publications/icvs/(external link)

United Nations (UN)

The UN Office on Drugs and Crime (UNODC) collects data on crime and the operation of criminal justice systems. Periodic reports on selected crime issues provide in-depth analysis on key topics of concern at the global and regional level. More information can be found at unodc.org/unodc/en/data-and-analysis/statistics/crime.html(external link)

How to compare NZCASS statistics with Police statistics here and overseas

This page was last updated: 04th March 2020