Crime rates may stay high for the next seven years because of a "baby blip" which peaked in 1990.
The famous postwar baby boom, which produced a peak of just over 65,000 births a year around 1960, faded away with the impact of the contraceptive pill. It reached a low
point of just under 50,000 births in 1982.
But as the children born in the baby boom began to have children themselves in the late 1980s, births increased again to peak at 60,153 in 1990. The number of births has since fallen, to 58,073 in 2004.
The children born in that baby blip produced surges in primary school enrolments in the early 1990s and in secondary schools around the start of this century.
They are now flowing into the prime criminal age group of 15 to 24.
Numbers in the 15 to 24 age group dropped from 583,000 in 1986 to 534,000 in 2001, but jumped to 596,000 last year.
A Department of Corrections researcher, Michael Rich, forecast in 2000 that the predictable surge in the criminal age group would push up crime rates in the four regions of fastest population growth until 2013.
"Approximately 80 per cent of the total change in offender numbers [84 per cent for the Community Probation Service, 80 per cent for the Public Prison Service] by 2013 will occur in Northland, Auckland, Waikato and Bay of Plenty," he wrote.
"The representation in the 15-19 and 20-24 ... age classes will increase notably [16 to 20 per cent] as children currently under offending age grow and mature."
However, yesterday's police statistics show that the overall crime rate has fallen. It has dropped from 1280 offences for every 10,000 people in the total population in 1996, to 994 last year, despite the rising numbers in the prime criminal age bracket.
