The Press FRIDAY, JULY 16, 1971. Population trends

Press, Volume CXI, Issue 32660, 16 July 1971, Page 8

The Press FRIDAY, JULY 16, 1971. Population trends

We print this morning a reply from the South Canterbury public relations officer (Mr A. S. Abernethy) to a leading article on population trends printed by “The Press” on Monday. We also print a summary of population trends in New Zealand over the last 100 years, to show the dangers of any attempt, such as Mr Abernethy’s, to forecast population trends from the figures of the last 10 years. It is true that the South Island’s share of the national increase in population fell from 20.4 per cent —not 29.3 per cent, as stated by Mr Abernethy—in 1961-66 to 14.5 per cent in 1966-71 From this fact Mr Abernethy argues, inexplicably, that the South Island’s share of the population increase will fall to 5.9 per cent in 1971-76, and that the South Island population will actually decline some time after 1978. In two previous intercensal periods the South Island's share of the New Zealand population growth has been lower than 14.5 per cent In 1911-16 the South Island accounted for only 3.9 per cent of the population increase, and in 1936-45 the South Island accounted for less than 0.1 per cent of the population growth. ' (Did the South Island send a higher proportion of its men to both wars?) Yet in the succeeding intercensal periods the South Island contributed 24.4 per cent (in 1916-21) and 29.4 per cent (in 1945-51) of the national increase. There is, therefore, no reason to expect an unusually low South Island contribution to population growth in one intercensal period to be followed by a further decline; and no-one with an elementary knowledge of statistical procedures would expect to find such a connection.

There is, however, a connection between increases in the South Island population and increases in the national population. In every intercensal period since 1874-78 the South Island’s population has risen less rapidly than the total population. For instance, between 1881 and 1886 the total population rose 18.1 per cent, but the South Island’s rose only 10.5 per cent; and between 1961 and 1966 the figures were 12.1 per cent and 7.3 per cent respectively. In the earlier period the ratio of the South Island’s increase to the national increase was .58 to 1, and in the later period the ratio was .60 to 1. In absolute terms, the South Island population has increased since the Second World War—excepting the last intercensal period—between 51,000 and 70,000 every five years. The calculations in the previous paragraph ignore the figures of the last five years, on which Mr Abernethy’s predictions are based. A study of the 1966-71 years shows that they are exceptional. Annual population totals published in the Monthly Abstract of Statistics show a population increase of 2.5 per cent in 1961, falling to 1.9 per cent in 1965; in the succeeding years the figures were 1.8, 1.3, 1.1, 1.2, and 1.8 respectively. The 1967-69 recession and consequent emigration are primarily responsible for the exceptionally low population increases in that intercensal period.

The Government Statistician has published population “ projections ” —which are not the same as forecasts—up to the year 2000. On the assumption of annual immigration of 5000—which may be compared with actual immigration last year of nearly 8500— these projections show five-yearly population increases between 9.1 per cent and 9.9 per cent for the next 30 years. If Mr Abernethy still predicts a declining South Island population he must assume either a more serious depression than that of 1967-69 or—against the trend of the last 100 years—a South Island population declining while the total population is rising.