Are Māori and Pacific people really over-represented in taser stats?

Today’s NZ Herald reports that Māori and Pacific Islanders are highly represented in the statistics for the use of tasers by the NZ police. Green MP Keith Locke is quoted as saying “Certainly they’re being fired disproportionately at Māori.” Mana Party spokeswoman Annette Sykes is quoted as saying “there has been this disproportionate outcome for Māori and Polynesian individuals, which is a sad indictment on us.”

Looking at the numbers, a taser has been used 35 times out of a total of 88 on Māori, or just under 40%. This is certainly much higher than 15% reported for the percentage of Māori from the 2006 census. However, this is not the relevant population. Rather, we should consider the proportion of Māori involved in the criminal justice system.

Figure 1, on page 17 of the report on Identifying and Responding to Bias in the Criminal Justice System: A Review of International and New Zealand Research (Bronwyn Morrison, Ministry of Justice 2009: p17) shows that approximately 40% of individuals involved New Zealand criminal justice system (in 2006) were Māori. These figures support the statement by Police Minister, Judith Collins that “the figures merely reflect the “sad fact” that Māori are over-represented in crime statistics.”

For those of you who like the statistics, then assuming a binomial model, the probability of observing 35 or more out of 88 incidents with p = 0.4, is approximately 0.47.

What do we take from this? Māori are not over-represented in the taser statistics. They occur in almost exactly the same proportion as they do in all other aspects of the criminal justice system.