Maori imprisonment rate climbing

Yesterday I posted about the Maori percentage of the prison population remaining at roughly one half since at least 1987. On the face of it this would appear at least better than it continuing to rise. Then it occurred to me (thanks to some prompting) that with a growing prison population, to maintain a 50 percent share the Maori rate of imprisonment would actually have to be increasing. A commentator said;

For what it's worth, not necessarily because Maori are increasing --- both absolutely, and relatively as a proportion of NZ's total population.

The question is: is the increase of prison population as a %age greater than the increase of maori as a %age. I'd guess, actually, that the answer is no.

To do this properly, don't fuck about with ratios and %ages. Get the raw numbers and work from there.

Never one to shirk a challenge I first looked to see if the statistics were already available. A search turned up this chart.



Note that this represents sentenced prisoners only and the population used was 14 and over.

The last prison census conducted was in 2003. There are statistics available for December 2009 which provide total prisoners and ethnicity but not a gender breakdown by ethnicity. Therefore I have made the assumption that 57% of the female prisoners were Maori (consistent with 2003) and removed 281 from the Maori total.

Prison population at December 2009; 8,244

Maori percentage; 50.8 % or 4,188 (- 281 females = 3,907)

Maori male aged 14 and older in 2009; 223,693

Rate per 1,000 17.47

Total prison population at November, 2003; 6,240

Male Maori prison population; 2,913

Maori male aged 14 and older in 2003; 202,506

Rate per 1,000 14.38

The population statistics used are from Statistics NZ estimates.

So the imprisonment rate per 1,000 Maori males has increased from 14.38 in 2003 to 17.47 in 2009. The only weakness in the data is my assumption about the percentage of Maori prisoners who are female.

(And of course whether more prisoners are simply identifying as primarily Maori is another factor I have no information about.)